# Calendar

Calendar
You are encouraged to solve this task according to the task description, using any language you may know.

Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices:

• A line printer with a width of 132 characters.
• An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43.

(Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.)

Kudos (κῦδος) for routines that also correctly transition from Julian to Gregorian calendar in September 1752.

This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983.

THE REAL PROGRAMMER'S NATURAL HABITAT
"Taped to the wall is a line-printer Snoopy calender for the year 1969."

For further Kudos see task CALENDAR, where all code is to be in UPPERCASE.

For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder.

For other calendar-related tasks, see Five weekends.

## Ada

We first specify a "Printable_Calendar" package (printable_calendar.ads). One can easily override the default names for weekdays and months, see the Calendar_-_for_"real"_programmers#Ada task.

with Ada.Calendar.Formatting;

package Printable_Calendar is

subtype String20 is String(1 .. 20);
type Month_Rep_Type is array (Ada.Calendar.Month_Number) of String20;

type Description is record
Weekday_Rep: String20;
Month_Rep: Month_Rep_Type;
end record;
-- for internationalization, you only need to define a new description

Default_Description: constant Description :=
(Weekday_Rep =>
"Mo Tu We Th Fr Sa So",
Month_Rep =>
(" January ", " February ", " March ",
" April ", " May ", " June ",
" July ", " August ", " September ",
" October ", " November ", " December "));

type Calendar (<>) is tagged private;

-- Initialize a calendar for devices with 80- or 132-characters per row
function Init_80(Des: Description := Default_Description) return Calendar;
function Init_132(Des: Description := Default_Description) return Calendar;

-- the following procedures output to standard IO; override if neccessary
procedure New_Line(Cal: Calendar);
procedure Put_String(Cal: Calendar; S: String);

-- the following procedures do the real stuff
procedure Print_Line_Centered(Cal: Calendar'Class; Line: String);
procedure Print(Cal: Calendar'Class;
Year: Ada.Calendar.Year_Number;
Year_String: String); -- this is the main Thing

private
type Calendar is tagged record
Columns, Rows, Space_Between_Columns: Positive;
Left_Space: Natural;

Weekday_Rep: String20;
Month_Rep: Month_Rep_Type;
end record;

end Printable_Calendar;

We continue with the implementation (printable_calendar.ads):

with Ada.Text_IO;

package body Printable_Calendar is

use Ada.Calendar;
package F renames Ada.Calendar.Formatting;

function Days_Per_Month(Year: Year_Number; Month: Month_Number)
return Day_Number is
begin
case Month is
when 1 | 3 | 5 | 7 | 8 | 10 | 12 => return 31;
when 4 | 6 | 9 | 11 => return 30;
when 2 =>
if Year mod 4 /= 0 then
return 28;
elsif Year mod 100 /= 0 then
return 29;
elsif Year mod 400 /= 0 then
return 28;
else
return 29;
end if;
end case;
end Days_Per_Month;

type Full_Month_Rep is array (1 .. 6) of String20;
function Generate_Printable_Month (Y: Ada.Calendar.Year_Number;
M: Ada.Calendar.Month_Number)
return Full_Month_Rep is

X: Full_Month_Rep := (others => " ");
-- If X=Generate_Printable_Month(2011, 01), the result could be
-- " January ", -- Month_Rep(01)
-- "Mo Tu We Th Fr Sa Su" -- Weekday_Rep
-- " 1 2" -- X(1)
-- " 3 4 5 6 7 8 9" -- X(2)
-- "10 11 12 13 14 15 16" -- X(3)
-- "17 18 19 20 21 22 23" -- X(4)
-- "24 25 26 27 28 29 30" -- X(5)
-- "31 " -- X(6)

Row: Integer range 1 .. 6  := 1;
Day_Index: constant array(F.Day_Name) of Positive
:= (1, 4, 7, 10, 13, 16, 19);
begin
for I in 1 .. Days_Per_Month(Y, M) loop
declare
Weekday: constant F.Day_Name  := F.Day_Of_Week(F.Time_Of(Y, M, I));
Pos: constant Positive  := Day_Index(Weekday);
Cleartext_Name: constant String := Day_Number'Image(I);
L: constant Positive  := Cleartext_Name'Last;
begin
X(Row)(Pos .. Pos+1) := Cleartext_Name(L-1 .. L);
if F."="(Weekday, F.Sunday) then
Row := Row + 1;
end if;
end;
end loop;
return X;
end Generate_Printable_Month;

procedure Print(Cal: Calendar'class;
Year: Ada.Calendar.Year_Number;
Year_String: String) is

The_Month: Month_Number := Month_Number'First;

procedure Write_Space(Length: Natural) is
begin
for I in 1 .. Length loop
Cal.Put_String(" ");
end loop;
end Write_Space;

Year_Rep: array(Month_Number) of Full_Month_Rep;

begin
-- print the year
Cal.Print_Line_Centered(Year_String);

-- generate a printable form for all the months
for Month in Month_Number loop
Year_Rep(Month) := Generate_Printable_Month(Year, Month);
end loop;

begin
while True loop

-- new line
Cal.New_Line;

-- write month names
Write_Space(Cal.Left_Space);
for Month in The_Month .. The_Month+Cal.Columns-2 loop
Cal.Put_String(Cal.Month_Rep(Month));
Write_Space(Cal.Space_Between_Columns);
end loop;
Cal.Put_String(Cal.Month_Rep(The_Month+Cal.Columns-1));
Cal.New_Line;

-- write "Mo Tu .. So" - or whatever is defined by Weekday_Rep
Write_Space(Cal.Left_Space);
for Month in The_Month .. The_Month+Cal.Columns-2 loop
Cal.Put_String(Cal.Weekday_Rep);
Write_Space(Cal.Space_Between_Columns);
end loop;
Cal.Put_String(Cal.Weekday_Rep);
Cal.New_Line;

-- write the dates
for I in 1 .. 6 loop
Write_Space(Cal.Left_Space);
for Month in The_Month .. The_Month+Cal.Columns-2 loop
Cal.Put_String(Year_Rep(Month)(I));
Write_Space(Cal.Space_Between_Columns);
end loop;
Cal.Put_String(Year_Rep(The_Month+Cal.Columns-1)(I));
Cal.New_Line;
end loop;

The_Month := The_Month + Cal.Columns;
-- this will eventually raise Constraint_Error to terminate the loop
end loop;
exception
when Constraint_Error => null;
end;
end Print;

procedure New_Line(Cal: Calendar) is
begin
Ada.Text_IO.New_Line;
end New_Line;

procedure Put_String(Cal: Calendar; S: String) is
begin
Ada.Text_IO.Put(S);
end Put_String;

procedure Print_Line_Centered(Cal: Calendar'Class; Line: String) is
Width : constant Positive := Cal.Columns*20
+ (Cal.Columns-1)*Cal.Space_Between_Columns
+ Cal.Left_Space;
begin
if Line'Length >= Width-1 then
Cal.Put_String(Line);
Cal.New_Line;
else
Print_Line_Centered(Cal, " " & Line & " ");
end if;
end Print_Line_Centered;

function Init_80(Des: Description := Default_Description) return Calendar is
X: Calendar:=
(Columns => 3, Rows => 4, Space_Between_Columns => 4,
Left_Space => 1,
Weekday_Rep => Des.Weekday_Rep,
Month_Rep => Des.Month_Rep
);
begin
return X;
end Init_80;

function Init_132(Des: Description := Default_Description) return Calendar is
X: Calendar:=
(Columns => 6, Rows => 2, Space_Between_Columns => 2,
Left_Space => 1,
Weekday_Rep => Des.Weekday_Rep,
Month_Rep => Des.Month_Rep
);
begin
return X;
end Init_132;

end Printable_Calendar;

Now, the main program is really simple:

with Printable_Calendar;

procedure Cal is

C: Printable_Calendar.Calendar := Printable_Calendar.Init_80;

begin
C.Print_Line_Centered("[reserved for Snoopy]");
C.New_Line;
C.Print(1969, "Nineteen-Sixty-Nine");
end Cal;

Here is the output:

[reserved for Snoopy]

Nineteen-Sixty-Nine

January                 February                 March
Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So
1  2  3  4  5                    1  2                    1  2
6  7  8  9 10 11 12     3  4  5  6  7  8  9     3  4  5  6  7  8  9
13 14 15 16 17 18 19    10 11 12 13 14 15 16    10 11 12 13 14 15 16
20 21 22 23 24 25 26    17 18 19 20 21 22 23    17 18 19 20 21 22 23
27 28 29 30 31          24 25 26 27 28          24 25 26 27 28 29 30
31

April                    May                     June
Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So
1  2  3  4  5  6              1  2  3  4                       1
7  8  9 10 11 12 13     5  6  7  8  9 10 11     2  3  4  5  6  7  8
14 15 16 17 18 19 20    12 13 14 15 16 17 18     9 10 11 12 13 14 15
21 22 23 24 25 26 27    19 20 21 22 23 24 25    16 17 18 19 20 21 22
28 29 30                26 27 28 29 30 31       23 24 25 26 27 28 29
30

July                   August                 September
Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So
1  2  3  4  5  6                 1  2  3     1  2  3  4  5  6  7
7  8  9 10 11 12 13     4  5  6  7  8  9 10     8  9 10 11 12 13 14
14 15 16 17 18 19 20    11 12 13 14 15 16 17    15 16 17 18 19 20 21
21 22 23 24 25 26 27    18 19 20 21 22 23 24    22 23 24 25 26 27 28
28 29 30 31             25 26 27 28 29 30 31    29 30

October                November                December
Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So    Mo Tu We Th Fr Sa So
1  2  3  4  5                    1  2     1  2  3  4  5  6  7
6  7  8  9 10 11 12     3  4  5  6  7  8  9     8  9 10 11 12 13 14
13 14 15 16 17 18 19    10 11 12 13 14 15 16    15 16 17 18 19 20 21
20 21 22 23 24 25 26    17 18 19 20 21 22 23    22 23 24 25 26 27 28
27 28 29 30 31          24 25 26 27 28 29 30    29 30 31

To get a 132-character-wide output, you just have to replace "Init_80" by "Init_132" in the main program.

## ALGOL 68

Works with: ALGOL 68 version Revision 1 - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny.
#!/usr/local/bin/a68g --script #

PROC print calendar = (INT year, page width)VOID: (

[]STRING month names = (
"January","February","March","April","May","June",
"July","August","September","October","November","December"),
weekday names = ("Su","Mo","Tu","We","Th","Fr","Sa");
FORMAT weekday fmt = $g,n(UPB weekday names - LWB weekday names)(" "g)$;

# Juggle the calendar format to fit the printer/screen width #
INT day width = UPB weekday names[1], day gap=1;
INT month width = (day width+day gap) * UPB weekday names-1;
INT month heading lines = 2;
INT month lines = (31 OVER UPB weekday names+month heading lines+2); # +2 for head/tail weeks #
INT year cols = (page width+1) OVER (month width+1);
INT year rows = (UPB month names-1)OVER year cols + 1;
INT month gap = (page width - year cols*month width + 1)OVER year cols;
INT year width = year cols*(month width+month gap)-month gap;
INT year lines = year rows*month lines;

MODE MONTHBOX = [month lines, month width]CHAR;
MODE YEARBOX = [year lines, year width]CHAR;

INT week start = 1; # Sunday #

PROC days in month = (INT year, month)INT:
CASE month IN 31,
IF year MOD 4 EQ 0 AND year MOD 100 NE 0 OR year MOD 400 EQ 0 THEN 29 ELSE 28 FI,
31, 30, 31, 30, 31, 31, 30, 31, 30, 31
ESAC;

PROC day of week = (INT year, month, day)INT: (
# Day of the week by Zeller’s Congruence algorithm from 1887 #
INT y := year, m := month, d := day, c;
IF m <= 2 THEN m +:= 12; y -:= 1 FI;
c := y OVER 100;
y %*:= 100;
(d - 1 + ((m + 1) * 26) OVER 10 + y + y OVER 4 + c OVER 4 - 2 * c) MOD 7
);

MODE SIMPLEOUT = UNION(STRING, []STRING, INT);

PROC cputf = (REF[]CHAR out, FORMAT fmt, SIMPLEOUT argv)VOID:(
FILE f; STRING s; associate(f,s);
putf(f, (fmt, argv));
out[:UPB s]:=s;
close(f)
);

PROC month repr = (INT year, month)MONTHBOX:(
MONTHBOX month box; FOR line TO UPB month box DO month box[line,]:=" "* 2 UPB month box OD;
STRING month name = month names[month];

# center the title #
cputf(month box[1,(month width - UPB month name ) OVER 2+1:], $g$, month name);
cputf(month box[2,], weekday fmt, weekday names);

INT first day := day of week(year, month, 1);
FOR day TO days in month(year, month) DO
INT line = (day+first day-week start) OVER UPB weekday names + month heading lines + 1;
INT char =((day+first day-week start) MOD UPB weekday names)*(day width+day gap) + 1;
cputf(month box[line,char:char+day width-1],$g(-day width)$, day)
OD;
month box
);

PROC year repr = (INT year)YEARBOX:(
YEARBOX year box;
FOR line TO UPB year box DO year box[line,]:=" "* 2 UPB year box OD;
FOR month row FROM 0 TO year rows-1 DO
FOR month col FROM 0 TO year cols-1 DO
INT month = month row * year cols + month col + 1;
IF month > UPB month names THEN
done
ELSE
INT month col width = month width+month gap;
year box[
month row*month lines+1 : (month row+1)*month lines,
month col*month col width+1 : (month col+1)*month col width-month gap
] := month repr(year, month)
FI
OD
OD;
done: year box
);

INT center = (year cols*(month width+month gap) - month gap - 1) OVER 2;
INT indent = (page width - year width) OVER 2;

printf((
$n(indent + center - 9)k g l$, "[Insert Snoopy here]",
$n(indent + center - 1)k 4d l$, year, $l$,
$n(indent)k n(year width)(g) l$, year repr(year)
))
);

main: (
CO inspired by http://www.ee.ryerson.ca/~elf/hack/realmen.html
Real Programmers Don't Use PASCAL - Ed Post
Datamation, volume 29 number 7, July 1983
THE REAL PROGRAMMER'S NATURAL HABITAT
"Taped to the wall is a line-printer Snoopy calender for the year 1969."
CO
INT mankind stepped on the moon = 1969,
line printer width = 80; # as at 1969! #
print calendar(mankind stepped on the moon, line printer width)
)

Output:

[Insert Snoopy here]
1969

January                    February                    March
Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa
1  2  3  4                          1                          1
5  6  7  8  9 10 11        2  3  4  5  6  7  8        2  3  4  5  6  7  8
12 13 14 15 16 17 18        9 10 11 12 13 14 15        9 10 11 12 13 14 15
19 20 21 22 23 24 25       16 17 18 19 20 21 22       16 17 18 19 20 21 22
26 27 28 29 30 31          23 24 25 26 27 28          23 24 25 26 27 28 29
30 31
April                       May                        June
Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa
1  2  3  4  5                    1  2  3        1  2  3  4  5  6  7
6  7  8  9 10 11 12        4  5  6  7  8  9 10        8  9 10 11 12 13 14
13 14 15 16 17 18 19       11 12 13 14 15 16 17       15 16 17 18 19 20 21
20 21 22 23 24 25 26       18 19 20 21 22 23 24       22 23 24 25 26 27 28
27 28 29 30                25 26 27 28 29 30 31       29 30

July                      August                   September
Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa
1  2  3  4  5                       1  2           1  2  3  4  5  6
6  7  8  9 10 11 12        3  4  5  6  7  8  9        7  8  9 10 11 12 13
13 14 15 16 17 18 19       10 11 12 13 14 15 16       14 15 16 17 18 19 20
20 21 22 23 24 25 26       17 18 19 20 21 22 23       21 22 23 24 25 26 27
27 28 29 30 31             24 25 26 27 28 29 30       28 29 30
31
October                    November                   December
Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa       Su Mo Tu We Th Fr Sa
1  2  3  4                          1           1  2  3  4  5  6
5  6  7  8  9 10 11        2  3  4  5  6  7  8        7  8  9 10 11 12 13
12 13 14 15 16 17 18        9 10 11 12 13 14 15       14 15 16 17 18 19 20
19 20 21 22 23 24 25       16 17 18 19 20 21 22       21 22 23 24 25 26 27
26 27 28 29 30 31          23 24 25 26 27 28 29       28 29 30 31
30

## AutoHotkey

Calendar(Yr){
LastDay := [], Day := []
Titles =
(ltrim
______January_________________February_________________March_______
_______April____________________May____________________June________
________July___________________August_________________September_____
______October_________________November________________December______
)
StringSplit, title, titles, n
Res := "________________________________" Yr "rn"

loop 4 { ; 4 Vertical Sections
Day[1]:=Yr SubStr("0" A_Index*3 -2, -1) 01
Day[2]:=Yr SubStr("0" A_Index*3 -1, -1) 01
Day[3]:=Yr SubStr("0" A_Index*3 , -1) 01
Res .= "rn" title%A_Index% "rnSu Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa"
loop , 6 { ; 6 Weeks max per month
Week := A_Index, Res .= "rn"
loop, 21 { ; 3 weeks times 7 days
Mon := Ceil(A_Index/7), ThisWD := Mod(A_Index-1,7)+1
FormatTime, WD, % Day[Mon], WDay
FormatTime, dd, % Day[Mon], dd
if (WD>ThisWD) {
Res .= "__ "
continue
}
dd := ((Week>3) && dd <10) ? "__" : dd, Res .= dd " ", LastDay[Mon] := Day[Mon], Day[Mon] +=1, Days
Res .= ((wd=7) && A_Index < 21) ? "___" : ""
FormatTime, dd, % Day[Mon], dd
}
}
Res .= "rn"
}
StringReplace, Res, Res,_,%A_Space%, all
Res:=RegExReplace(Res,"am)(^|\s)\K0", " ")
return res
}
Examples:
Gui, font,s8, COURIER
Gui, add, edit, vYr w40 r1 Limit4 Number, 1969
Gui, add, edit, vEdit2 w580 r38
Gui, Add, Button, Default Hidden gSubmit
Gui, show

Submit:
Gui, Submit, NoHide
GuiControl,, Edit2, % Calendar(Yr)
return

GuiEscape:
GuiClose:
ExitApp
return
Outputs:
1969

January                February                  March
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1                       1
5  6  7  8  9 10 11     2  3  4  5  6  7  8     2  3  4  5  6  7  8
12 13 14 15 16 17 18     9 10 11 12 13 14 15     9 10 11 12 13 14 15
19 20 21 22 23 24 25    16 17 18 19 20 21 22    16 17 18 19 20 21 22
26 27 28 29 30 31       23 24 25 26 27 28       23 24 25 26 27 28 29
30 31

April                    May                    June
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                 1  2  3     1  2  3  4  5  6  7
6  7  8  9 10 11 12     4  5  6  7  8  9 10     8  9 10 11 12 13 14
13 14 15 16 17 18 19    11 12 13 14 15 16 17    15 16 17 18 19 20 21
20 21 22 23 24 25 26    18 19 20 21 22 23 24    22 23 24 25 26 27 28
27 28 29 30             25 26 27 28 29 30 31    29 30

July                   August                 September
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                    1  2        1  2  3  4  5  6
6  7  8  9 10 11 12     3  4  5  6  7  8  9     7  8  9 10 11 12 13
13 14 15 16 17 18 19    10 11 12 13 14 15 16    14 15 16 17 18 19 20
20 21 22 23 24 25 26    17 18 19 20 21 22 23    21 22 23 24 25 26 27
27 28 29 30 31          24 25 26 27 28 29 30    28 29 30
31

October                November                December
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1        1  2  3  4  5  6
5  6  7  8  9 10 11     2  3  4  5  6  7  8     7  8  9 10 11 12 13
12 13 14 15 16 17 18     9 10 11 12 13 14 15    14 15 16 17 18 19 20
19 20 21 22 23 24 25    16 17 18 19 20 21 22    21 22 23 24 25 26 27
26 27 28 29 30 31       23 24 25 26 27 28 29    28 29 30 31
30

## AutoIt

#include <Date.au3>

; Set the count of characters in each line, minimum is 20 - one month.
Global $iPrintSize = 132 ; Set the count of months, you want to print side by side. With "0" it calculates automatically. ; The number will corrected, if it not allowed to print in an rectangle. ; If your print size is to small for given count, it will set back to automatically calculation. Global$iSideBySide = 3

; Set the count of spaces between months.
Global $iSpace = 4 _CreateCalendar( 1969 ) Func _CreateCalendar($_iYear)
Local $aMon[12] = [' January ', ' February ', ' March ', _ ' April ', ' May ', ' June ', _ ' July ', ' August ', ' September ', _ ' October ', ' November ', ' December '] Local$sHead = 'Mo Tu We Th Fr Sa Su'
Local $aDaysInMonth[12] = [31,28,31,30,31,30,31,31,30,31,30,31] If _DateIsLeapYear($_iYear) Then $aDaysInMonth[1] = 29 ; == assign date in weekday table for the whole year Local$aAllDaysInMonth[6][7][12] ; [ lines ][ weekdays ][ months ]
Local $iDay = 1,$iShift
For $i = 1 To 12$iShift = _DateToDayOfWeekISO($_iYear,$i, 1) -1
For $j = 0 To 5 For$k = $iShift To 6$aAllDaysInMonth[$j][$k][$i-1] =$iDay
$iDay += 1 If$iDay > $aDaysInMonth[$i-1] Then ExitLoop(2)
Next
$iShift = 0 Next$iDay = 1
Next

; == check given side by side count, calculate if needed
If $iSideBySide > 0 Then If$iPrintSize < ($iSideBySide *(20 +$iSpace) -$iSpace) Then$iSideBySide = 0
EndIf
Switch $iSideBySide Case 0$iSideBySide = Int($iPrintSize /(20 +$iSpace))
If $iPrintSize < 20 Then Return _PrintLine('Escape: Size Error') If$iPrintSize < (20 +$iSpace) Then$iSideBySide = 1
Case 5
$iSideBySide = 4 Case 7 To 11$iSideBySide = 6
EndSwitch

; == create space string
Local $sSpace = '' For$i = 1 To $iSpace$sSpace &= ' '
Next

; == print header
_PrintLine(@LF)
_PrintLine('[ here is Snoopy ]', @LF)
_PrintLine(StringRegExpReplace($_iYear, '(\d)(\d)(\d)(\d)', '$1 $2$3 $4'), @LF) ; == create data for each line, in dependence to count of months in one line Local$sLine, $iRight,$sTmp1, $sTmp2 For$n = 0 To 12 /$iSideBySide -1$sTmp1 = ''
$sTmp2 = '' For$z = 0 To $iSideBySide -1$sTmp1 &= $aMon[$iSideBySide *$n+$z] & $sSpace$sTmp2 &= $sHead &$sSpace
Next
_PrintLine(StringTrimRight($sTmp1,$iSpace))
_PrintLine(StringTrimRight($sTmp2,$iSpace))
For $j = 0 To 5$sLine = ''
For $i = 1 To$iSideBySide
For $k = 0 To 6$iRight = 3
If $k = 0 Then$iRight = 2
$sLine &= StringRight(' ' &$aAllDaysInMonth[$j][$k][$iSideBySide*$n+$i-1],$iRight)
Next
If $i <$iSideBySide Then $sLine &=$sSpace
Next
_PrintLine($sLine) Next Next EndFunc ;==>_CreateCalendar Func _PrintLine($_sLine, $_sLF='') Local$iLen = StringLen($_sLine) Local$sSpace = '', $sLeft = '' For$i = 1 To $iPrintSize-1$sSpace &= ' '
Next
If $iLen <$iPrintSize Then $sLeft = StringLeft($sSpace, Int(($iPrintSize-$iLen)/2))
ConsoleWrite($sLeft &$_sLine & $_sLF & @LF) EndFunc ;==>_PrintLine Output [ here is Snoopy ] 1 9 6 9 January February March Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 6 7 8 9 10 11 12 3 4 5 6 7 8 9 3 4 5 6 7 8 9 13 14 15 16 17 18 19 10 11 12 13 14 15 16 10 11 12 13 14 15 16 20 21 22 23 24 25 26 17 18 19 20 21 22 23 17 18 19 20 21 22 23 27 28 29 30 31 24 25 26 27 28 24 25 26 27 28 29 30 31 April May June Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 4 1 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 30 July August September Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 1 2 3 4 5 6 7 7 8 9 10 11 12 13 4 5 6 7 8 9 10 8 9 10 11 12 13 14 14 15 16 17 18 19 20 11 12 13 14 15 16 17 15 16 17 18 19 20 21 21 22 23 24 25 26 27 18 19 20 21 22 23 24 22 23 24 25 26 27 28 28 29 30 31 25 26 27 28 29 30 31 29 30 October November December Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 3 4 5 6 7 6 7 8 9 10 11 12 3 4 5 6 7 8 9 8 9 10 11 12 13 14 13 14 15 16 17 18 19 10 11 12 13 14 15 16 15 16 17 18 19 20 21 20 21 22 23 24 25 26 17 18 19 20 21 22 23 22 23 24 25 26 27 28 27 28 29 30 31 24 25 26 27 28 29 30 29 30 31 --BugFix (talk) 00:40, 15 November 2013 (UTC) ## AWK Works with Gnu awk version 3.1.5 and with BusyBox v1.20.0.git awk To change the output width, change the value assigned to variable pagewide #!/bin/gawk -f BEGIN{ wkdays = "Su Mo Tu We Th Fr Sa" pagewide = 80 blank=" " for (i=1; i<pagewide; i++) blank = blank " " # month name accessed as substr(month,num*10,10) # where num is number of month, 1-12 month= " January February March April " month= month " May June July August " month= month " September October November December " # table of days per month accessed as substr(days,2*month,2) days =" 312831303130313130313031" line1 = "" line2 = "" line3 = "" line4 = "" line5 = "" line6 = "" line7 = "" line8 = "" # print " year: " year " starts on: " dow(year) } function center(text, half) { half = (pagewide - length(text))/2 return substr(blank,1,half) text substr(blank,1,half) } function min(a,b) { if (a < b) return a else return b } function makewk (fst,lst,day, i,wstring ){ wstring="" for (i=1;i<day;i++) wstring=wstring " " for (i=fst;i<=lst;i++) wstring=wstring sprintf("%2d ",i) return substr(wstring " ",1,20) } function dow (year, y){ y=year y= (y*365+int(y/4) - int(y/100) + int(y/400) +1) %7 # leap year adjustment leap = 0 if (year % 4 == 0) leap = 1 if (year % 100 == 0) leap = 0 if (year % 400 == 0) leap = 1 y = y - leap if (y==-1) y=6 if (y==0) y=7 return (y) } function prmonth (nmonth, newdow,monsize ){ line1 = line1 " " (substr(month,10*nmonth,10)) " " line2 = line2 (wkdays) " " line3 = line3 (makewk(1,8-newdow,newdow)) " " line4 = line4 (makewk(9-newdow,15-newdow,1)) " " line5 = line5 (makewk(16-newdow,22-newdow,1)) " " line6 = line6 (makewk(23-newdow,29-newdow,1)) " " line7 = line7 (makewk(30-newdow,min(monsize,36-newdow),1)) " " line8 = line8 (makewk(37-newdow,monsize,1)) " " if (length(line3) + 22 > pagewide) { print center(line1) print center(line2) print center(line3) print center(line4) print center(line5) print center(line6) print center(line7) print center(line8) line1 = "" line2 = "" line3 = "" line4 = "" line5 = "" line6 = "" line7 = "" line8 = "" } } /q/{ exit } { monsize=substr(days,2*1,2) newdow=dow($1)
print center("[ picture of Snoopy goes here ]")
print center(sprintf("%d",$1) ) # January - December for (i=1; i<13; i++) { prmonth(i,newdow,monsize) newdow=(monsize+newdow) %7 if (newdow == 0) newdow = 7 monsize=substr(days,2+2*i,2) if (leap == 1 && monsize == 28) monsize = 29 } } Output: [ picture of Snoopy goes here ] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 ## Batch File ::Calender Task from Rosetta Code Wiki ::Batch File Implementation @echo off setlocal enabledelayedexpansion %== Set a valid year [will not be validated] ==% set y=1969 %== Set the variables for months (feb_l=the normal 28 days) ==% set jan_l=31&set apr_l=30 set mar_l=31&set jun_l=30 set may_l=31&set sep_l=30 set jul_l=31&set nov_l=30 set aug_l=31&set feb_l=28 set oct_l=31 set dec_l=31 %== Compute day for first day of the year ==% set /a d=(y/4+y)-(y/100-y/400) %== Check if that year is a leap year ==% set /a "op1=y%%4","op2=y%%100","op3=y%%400" if not "%op1%"=="0" (goto :no_leap) if not "%op2%"=="0" (goto :yes_leap) if not "%op3%"=="0" (goto :no_leap) :yes_leap %== Ooops... Leap year. Change feb_l to 29. ==% set feb_l=29 set/a d-=1 :no_leap %== Compute weekday of the first day... ==% set /a d%%=7 %== Generate everything that's inside the calendar ==% for %%a in (jan feb mar apr may jun jul aug sep oct nov dec) do ( set %%a= set chars_added=0 for /l %%b in (1,1,!d!) do (set "%%a=!%%a! "&set /a chars_added+=3) for /l %%c in (1,1,!%%a_l!) do ( if %%c lss 10 (set "%%a=!%%a! %%c ") else (set "%%a=!%%a!%%c ") set /a chars_added+=3 ) for /l %%d in (!chars_added!,1,124) do set "%%a=!%%a! " set /a d=^(d+%%a_l^)%%7 ) %== Display the calendar ==% cls echo. echo. [SNOOPY] echo. echo. YEAR = %y% echo. echo. January February March echo. Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa echo. %jan:~0,20% %feb:~0,20% %mar:~0,20% echo. %jan:~21,20% %feb:~21,20% %mar:~21,20% echo. %jan:~42,20% %feb:~42,20% %mar:~42,20% echo. %jan:~63,20% %feb:~63,20% %mar:~63,20% echo. %jan:~84,20% %feb:~84,20% %mar:~84,20% echo. %jan:~105% %feb:~105% %mar:~105% echo. echo. April May June echo. Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa echo. %apr:~0,20% %may:~0,20% %jun:~0,20% echo. %apr:~21,20% %may:~21,20% %jun:~21,20% echo. %apr:~42,20% %may:~42,20% %jun:~42,20% echo. %apr:~63,20% %may:~63,20% %jun:~63,20% echo. %apr:~84,20% %may:~84,20% %jun:~84,20% echo. %apr:~105% %may:~105% %jun:~105% echo. echo. July August September echo. Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa echo. %jul:~0,20% %aug:~0,20% %sep:~0,20% echo. %jul:~21,20% %aug:~21,20% %sep:~21,20% echo. %jul:~42,20% %aug:~42,20% %sep:~42,20% echo. %jul:~63,20% %aug:~63,20% %sep:~63,20% echo. %jul:~84,20% %aug:~84,20% %sep:~84,20% echo. %jul:~105% %aug:~105% %sep:~105% echo. echo. October November December echo. Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa echo. %oct:~0,20% %nov:~0,20% %dec:~0,20% echo. %oct:~21,20% %nov:~21,20% %dec:~21,20% echo. %oct:~42,20% %nov:~42,20% %dec:~42,20% echo. %oct:~63,20% %nov:~63,20% %dec:~63,20% echo. %oct:~84,20% %nov:~84,20% %dec:~84,20% echo. %oct:~105% %nov:~105% %dec:~105% echo. pause endlocal Output: [SNOOPY] YEAR = 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 Press any key to continue . . . ## BBC BASIC The day and month names are in the language for which the PC is configured. INSTALL @lib$+"DATELIB"
VDU 23,22,640;570;8,15,16,128

year% = 1969
PRINT TAB(38); year%
DIM dom%(2), mjd%(2), dim%(2)

FOR day% = 1 TO 7
days$+= LEFT$(FN_date$(FN_mjd(day%, 1, 1905), "ddd"), 2) + " " NEXT FOR month% = 1 TO 10 STEP 3 PRINT FOR col% = 0 TO 2 mjd%(col%) = FN_mjd(1, month% + col%, year%) month$ = FN_date$(mjd%(col%), "MMMM") PRINT TAB(col%*24 + 16 - LEN(month$)/2) month$; NEXT FOR col% = 0 TO 2 PRINT TAB(col%*24 + 6) days$;
dim%(col%) = FN_dim(month% + col%, year%)
NEXT
dom%() = 1
col% = 0
REPEAT
dow% = FN_dow(mjd%(col%))
IF dom%(col%)<=dim%(col%) THEN
PRINT TAB(col%*24 + dow%*3 + 6); dom%(col%);
dom%(col%) += 1
mjd%(col%) += 1
ENDIF
IF dow%=6 OR dom%(col%)>dim%(col%) col% = (col% + 1) MOD 3
UNTIL dom%(0)>dim%(0) AND dom%(1)>dim%(1) AND dom%(2)>dim%(2)
PRINT
NEXT

Output:

1969

January                 February                 March
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1                       1
5  6  7  8  9  10 11    2  3  4  5  6  7  8     2  3  4  5  6  7  8
12 13 14 15 16 17 18    9  10 11 12 13 14 15    9  10 11 12 13 14 15
19 20 21 22 23 24 25    16 17 18 19 20 21 22    16 17 18 19 20 21 22
26 27 28 29 30 31       23 24 25 26 27 28       23 24 25 26 27 28 29
30 31

April                    May                     June
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                 1  2  3     1  2  3  4  5  6  7
6  7  8  9  10 11 12    4  5  6  7  8  9  10    8  9  10 11 12 13 14
13 14 15 16 17 18 19    11 12 13 14 15 16 17    15 16 17 18 19 20 21
20 21 22 23 24 25 26    18 19 20 21 22 23 24    22 23 24 25 26 27 28
27 28 29 30             25 26 27 28 29 30 31    29 30

July                   August                September
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                    1  2        1  2  3  4  5  6
6  7  8  9  10 11 12    3  4  5  6  7  8  9     7  8  9  10 11 12 13
13 14 15 16 17 18 19    10 11 12 13 14 15 16    14 15 16 17 18 19 20
20 21 22 23 24 25 26    17 18 19 20 21 22 23    21 22 23 24 25 26 27
27 28 29 30 31          24 25 26 27 28 29 30    28 29 30
31

October                 November                December
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1        1  2  3  4  5  6
5  6  7  8  9  10 11    2  3  4  5  6  7  8     7  8  9  10 11 12 13
12 13 14 15 16 17 18    9  10 11 12 13 14 15    14 15 16 17 18 19 20
19 20 21 22 23 24 25    16 17 18 19 20 21 22    21 22 23 24 25 26 27
26 27 28 29 30 31       23 24 25 26 27 28 29    28 29 30 31
30

## Befunge

This is quite closely based on the C sample, although the centering calculation has been adjusted to fix an off-by-one error, and the months have been made a constant height, regardless of how much space they require, to try and produce a more balanced layout.

The year is read from stdin, and the width is specified by the first value on the stack (set to 80 - "P" - in the current implementation).

"P"00p&>:::4%!\"d"%*\45*:*%!+!!65*+31p:1-:::"I"5**\4/+\"d"/-\45*:*/+1+7%:0v
J!F?M!A M!J J!A!S O!N D!SaFrThWeTuMoSuvp01:_1#!-#%:#\>#+6<v-2g1+1g01p1p01:<
January February March April >:45**00g\-\1-:v:<<6>+7%:10g2+:38*\|
May June July August v02-1:+4*-4\\4:/_$:^^:/*2+92+2:g00$$< September October November December>p:45*+10g*\--2/00g4-2/>:#,1#*-#8\#4_v >20g>:#,1#*-#8\#4_6"S" v. .vp040\_4#!8#\*#-,#1>#:<+5g03g01:,,:+55<0.p03< ^_v#:-1_v#!:,*84,g1+1,< < ^ >::4%9*40g:8!#v_$$$1+v^+g02_#v$#,$#+5<^_v#\<
-#8\#4_$7>1-:2*64*+:1g>^ ^ ^,g+2/4\+p04+1:<>1#\-#<:66+\^ >>$10g30g>:#,1#*
> > $$55+,6>>40p:10g30g>:#,1#*-#8\#4_>\:2*:1+1g2-50p1g640g-7*1+\-7v v@,<6 2:+g01_55+,^ > > > > #^>#g>#0>#2_v v*2!!\%+55:\/+55:**0\!g05:::\< >2-^^ ->:> >#^>#<>#<^#!:-1g04$$ < < < < < >4+8*+\:!!2*4+8*+,,48*,1+\1-:>#^_1+\1

## C

With arbitrary display width (>= 20 though) and auto spacing.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int width = 80, year = 1969;
int cols, lead, gap;

const char *wdays[] = { "Su", "Mo", "Tu", "We", "Th", "Fr", "Sa" };
struct months {
const char *name;
int days, start_wday, at;
} months[12] = {
{ "January", 31, 0, 0 },
{ "Februray", 28, 0, 0 },
{ "March", 31, 0, 0 },
{ "April", 30, 0, 0 },
{ "May", 31, 0, 0 },
{ "June", 30, 0, 0 },
{ "July", 31, 0, 0 },
{ "August", 31, 0, 0 },
{ "September", 30, 0, 0 },
{ "October", 31, 0, 0 },
{ "November", 30, 0, 0 },
{ "December", 31, 0, 0 }
};

void space(int n) { while (n-- > 0) putchar(' '); }

void init_months()
{
int i;

if ((!(year % 4) && (year % 100)) || !(year % 400))
months[1].days = 29;

year--;
months[0].start_wday
= (year * 365 + year/4 - year/100 + year/400 + 1) % 7;

for (i = 1; i < 12; i++)
months[i].start_wday =
(months[i-1].start_wday + months[i-1].days) % 7;

cols = (width + 2) / 22;
while (12 % cols) cols--;
gap = cols - 1 ? (width - 20 * cols) / (cols - 1) : 0;
if (gap > 4) gap = 4;
lead = (width - (20 + gap) * cols + gap + 1) / 2;
year++;
}

void print_row(int row)
{
int c, i, from = row * cols, to = from + cols;
space(lead);
for (c = from; c < to; c++) {
i = strlen(months[c].name);
space((20 - i)/2);
printf("%s", months[c].name);
space(20 - i - (20 - i)/2 + ((c == to - 1) ? 0 : gap));
}
putchar('\n');

space(lead);
for (c = from; c < to; c++) {
for (i = 0; i < 7; i++)
printf("%s%s", wdays[i], i == 6 ? "" : " ");
if (c < to - 1) space(gap);
else putchar('\n');
}

while (1) {
for (c = from; c < to; c++)
if (months[c].at < months[c].days) break;
if (c == to) break;

space(lead);
for (c = from; c < to; c++) {
for (i = 0; i < months[c].start_wday; i++) space(3);
while(i++ < 7 && months[c].at < months[c].days) {
printf("%2d", ++months[c].at);
if (i < 7 || c < to - 1) putchar(' ');
}
while (i++ <= 7 && c < to - 1) space(3);
if (c < to - 1) space(gap - 1);
months[c].start_wday = 0;
}
putchar('\n');
}
putchar('\n');
}

void print_year()
{
int row;
char buf[32];
sprintf(buf, "%d", year);
space((width - strlen(buf)) / 2);
printf("%s\n\n", buf);
for (row = 0; row * cols < 12; row++)
print_row(row);
}

int main(int c, char **v)
{
int i, year_set = 0;
for (i = 1; i < c; i++) {
if (!strcmp(v[i], "-w")) {
if (++i == c || (width = atoi(v[i])) < 20)
goto bail;
} else if (!year_set) {
if (!sscanf(v[i], "%d", &year) || year <= 0)
year = 1969;
year_set = 1;
} else
goto bail;
}

init_months();
print_year();
return 0;

bail: fprintf(stderr, "bad args\nUsage: %s year [-w width (>= 20)]\n", v[0]);
exit(1);
}

## C++

#include <windows.h>
#include <iostream>

//--------------------------------------------------------------------------------------------------
using namespace std;

//--------------------------------------------------------------------------------------------------
class calender
{
public:
void drawCalender( int y )
{
year = y;
for( int i = 0; i < 12; i++ )
firstdays[i] = getfirstday( i );

isleapyear();
build();
}

private:
void isleapyear()
{
isleap = false;

if( !( year % 4 ) )
{
if( year % 100 ) isleap = true;
else if( !( year % 400 ) ) isleap = true;
}
}

int getfirstday( int m )
{
int y = year;

int f = y + 1 + 3 * m - 1;
m++;
if( m < 3 ) y--;
else f -= int( .4 * m + 2.3 );

f += int( y / 4 ) - int( ( y / 100 + 1 ) * 0.75 );
f %= 7;

return f;
}

void build()
{
int days[] = { 31, isleap ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
int lc = 0, lco = 0, ystr = 7, start = 2, fd = 0, m = 0;
HANDLE h = GetStdHandle( STD_OUTPUT_HANDLE );
COORD pos = { 0, ystr };
draw();

for( int i = 0; i < 4; i++ )
{
for( int j = 0; j < 3; j++ )
{
int d = firstdays[fd++], dm = days[m++];
pos.X = d * 3 + start;
SetConsoleCursorPosition( h, pos );

for( int dd = 0; dd < dm; dd++ )
{
if( dd < 9 ) cout << 0 << dd + 1 << " ";
else cout << dd + 1 << " ";

pos.X += 3;
if( pos.X - start > 20 )
{
pos.X = start; pos.Y++;
SetConsoleCursorPosition( h, pos );
}
}

start += 23;
pos.X = start; pos.Y = ystr;
SetConsoleCursorPosition( h, pos );
}
ystr += 9; start = 2;
pos.Y = ystr;
}
}

void draw()
{
system( "cls" );
cout << "+--------------------------------------------------------------------+" << endl;
cout << "| [SNOOPY] |" << endl;
cout << "| |" << endl;
cout << "| == " << year << " == |" << endl;
cout << "+----------------------+----------------------+----------------------+" << endl;
cout << "| JANUARY | FEBRUARY | MARCH |" << endl;
cout << "| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "+----------------------+----------------------+----------------------+" << endl;
cout << "| APRIL | MAY | JUNE |" << endl;
cout << "| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "+----------------------+----------------------+----------------------+" << endl;
cout << "| JULY | AUGUST | SEPTEMBER |" << endl;
cout << "| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "+----------------------+----------------------+----------------------+" << endl;
cout << "| OCTOBER | NOVEMBER | DECEMBER |" << endl;
cout << "| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "| | | |" << endl;
cout << "+----------------------+----------------------+----------------------+" << endl;
}

int firstdays[12], year;
bool isleap;
};
//--------------------------------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
int y;
calender cal;

while( true )
{
system( "cls" );
cout << "Enter the year( yyyy ) --- ( 0 to quit ): ";
cin >> y;
if( !y ) return 0;

cal.drawCalender( y );
cout << endl << endl << endl << endl << endl << endl << endl << endl;

system( "pause" );
}
return 0;
}
//--------------------------------------------------------------------------------------------------

Output:

+--------------------------------------------------------------------+
|                              [SNOOPY]                              |
|                                                                    |
|                             == 1969 ==                             |
+----------------------+----------------------+----------------------+
|       JANUARY        |       FEBRUARY       |         MARCH        |
| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |
|          01 02 03 04 |                   01 |                   01 |
| 05 06 07 08 09 10 11 | 02 03 04 05 06 07 08 | 02 03 04 05 06 07 08 |
| 12 13 14 15 16 17 18 | 09 10 11 12 13 14 15 | 09 10 11 12 13 14 15 |
| 19 20 21 22 23 24 25 | 16 17 18 19 20 21 22 | 16 17 18 19 20 21 22 |
| 26 27 28 29 30 31    | 23 24 25 26 27 28    | 23 24 25 26 27 28 29 |
|                      |                      | 30 31                |
+----------------------+----------------------+----------------------+
|        APRIL         |          MAY         |         JUNE         |
| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |
|       01 02 03 04 05 |             01 02 03 | 01 02 03 04 05 06 07 |
| 06 07 08 09 10 11 12 | 04 05 06 07 08 09 10 | 08 09 10 11 12 13 14 |
| 13 14 15 16 17 18 19 | 11 12 13 14 15 16 17 | 15 16 17 18 19 20 21 |
| 20 21 22 23 24 25 26 | 18 19 20 21 22 23 24 | 22 23 24 25 26 27 28 |
| 27 28 29 30          | 25 26 27 28 29 30 31 | 29 30                |
|                      |                      |                      |
+----------------------+----------------------+----------------------+
|         JULY         |        AUGUST        |       SEPTEMBER      |
| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |
|       01 02 03 04 05 |                01 02 |    01 02 03 04 05 06 |
| 06 07 08 09 10 11 12 | 03 04 05 06 07 08 09 | 07 08 09 10 11 12 13 |
| 13 14 15 16 17 18 19 | 10 11 12 13 14 15 16 | 14 15 16 17 18 19 20 |
| 20 21 22 23 24 25 26 | 17 18 19 20 21 22 23 | 21 22 23 24 25 26 27 |
| 27 28 29 30 31       | 24 25 26 27 28 29 30 | 28 29 30             |
|                      | 31                   |                      |
+----------------------+----------------------+----------------------+
|        OCTOBER       |       NOVEMBER       |       DECEMBER       |
| SU MO TU WE TH FR SA | SU MO TU WE TH FR SA | SU MO TU WE TH FR SA |
|          01 02 03 04 |                   01 |    01 02 03 04 05 06 |
| 05 06 07 08 09 10 11 | 02 03 04 05 06 07 08 | 07 08 09 10 11 12 13 |
| 12 13 14 15 16 17 18 | 09 10 11 12 13 14 15 | 14 15 16 17 18 19 20 |
| 19 20 21 22 23 24 25 | 16 17 18 19 20 21 22 | 21 22 23 24 25 26 27 |
| 26 27 28 29 30 31    | 23 24 25 26 27 28 29 | 28 29 30 31          |
|                      | 30                   |                      |
+----------------------+----------------------+----------------------+

## C#

An attempt to abuse the DateTime class for all static information. In the event that the number of days and months changes, so long as the DateTime class is updated accordingly, this should still print properly. It also abuses iterators to allow for a concise month printing method, but with the ability to still print x months per line.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CalendarStuff
{

class Program
{
static void Main(string[] args)
{
Console.WindowHeight = 46;
Console.Write(buildMonths(new DateTime(1969, 1, 1)));
Console.Read();
}
private static string buildMonths(DateTime date)
{
StringBuilder sb = new StringBuilder();
sb.AppendLine(center("[Snoop]", 24 * 3));
sb.AppendLine();
sb.AppendLine(center(date.Year.ToString(), 24 * 3));

List<DateTime> dts = new List<DateTime>();
while (true)
{
dts.Add(date);
if (date.Year != ((date = date.AddMonths(1)).Year))
{
break;
}
}
var jd = dts.Select(a => buildMonth(a).GetEnumerator()).ToArray();

int sCur=0;
while (sCur<dts.Count)
{
sb.AppendLine();
int curMonth=0;
var j = jd.Where(a => curMonth++ >= sCur && curMonth - 1 < sCur + 3).ToArray(); //grab the next 3
sCur += j.Length;
bool breakOut = false;
while (!breakOut)
{
int inj = 1;
foreach (var cd in j)
{
if (cd.MoveNext())
{
sb.Append((cd.Current.Length == 21 ? cd.Current : cd.Current.PadRight(21, ' ')) + " ");
}
else
{
sb.Append("".PadRight(21, ' ') + " ");
breakOut = true;
}
if (inj++ % 3 == 0) sb.AppendLine();
}
}

}
return sb.ToString();
}

private static IEnumerable<string> buildMonth(DateTime date)
{
yield return center(date.ToString("MMMM"),7*3);
var j = DateTime.DaysInMonth(date.Year, date.Month);
yield return Enum.GetNames(typeof(DayOfWeek)).Aggregate("", (current, result) => current + (result.Substring(0, 2).ToUpper() + " "));
string cur = "";
int total = 0;

foreach (var day in Enumerable.Range(-((int)date.DayOfWeek),j + (int)date.DayOfWeek))
{
cur += (day < 0 ? " " : ((day < 9 ? " " : "") + (day + 1))) +" ";
if (total++ > 0 && (total ) % 7 == 0)
{
yield return cur;
cur = "";
}
}
yield return cur;
}
private static string center(string s, int len)
{
return (s.PadLeft((len - s.Length) / 2 + s.Length, ' ').PadRight((len), ' '));
}
}
}

## COBOL

the program calls subroutine DATE2DOW to convert any YYYY-MM-DD to Day of Week (1=Sunday). the group names WS-CFGN and WS-CFGW may be moved to WS-CFG to use narrow or wide print line size respectively.

IDENTIFICATION DIVISION.
PROGRAM-ID. CALEND.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
DATA DIVISION.

WORKING-STORAGE SECTION.
01 WS-DAY-NAMES-DEF.
03 FILLER PIC X(09) VALUE 'SUNDAY '.
03 FILLER PIC X(09) VALUE 'MONDAY '.
03 FILLER PIC X(09) VALUE 'TUESDAY '.
03 FILLER PIC X(09) VALUE 'WEDNESDAY'.
03 FILLER PIC X(09) VALUE 'THURSDAY '.
03 FILLER PIC X(09) VALUE 'FRIDAY '.
03 FILLER PIC X(09) VALUE 'SATURDAY '.
01 FILLER REDEFINES WS-DAY-NAMES-DEF.
03 WS-DAY-NAME PIC X(09) OCCURS 07 TIMES.

01 WS-MTH-INFO-DEF.
03 FILLER PIC X(11) VALUE 'JANUARY 31'.
03 FILLER PIC X(11) VALUE 'FEBRUARY 28'.
03 FILLER PIC X(11) VALUE 'MARCH 31'.
03 FILLER PIC X(11) VALUE 'APRIL 30'.
03 FILLER PIC X(11) VALUE 'MAY 31'.
03 FILLER PIC X(11) VALUE 'JUNE 30'.
03 FILLER PIC X(11) VALUE 'JULY 31'.
03 FILLER PIC X(11) VALUE 'AUGUST 31'.
03 FILLER PIC X(11) VALUE 'SEPTEMBER30'.
03 FILLER PIC X(11) VALUE 'OCTOBER 31'.
03 FILLER PIC X(11) VALUE 'NOVEMBER 30'.
03 FILLER PIC X(11) VALUE 'DECEMBER 31'.
01 FILLER REDEFINES WS-MTH-INFO-DEF.
03 WS-MTH-INFO-TABLE OCCURS 12 TIMES.
05 WS-MTH-INFO-NAME PIC X(09).
05 WS-MTH-INFO-DAYS PIC 9(02).

01 WS-MTH-AREA.
03 WS-MTH-DD PIC S99.
03 WS-DAY1 PIC 9.
03 WS-DAYS PIC 99.
03 WS-DD PIC 9.
03 WS-WK PIC 9.
03 WS-MM PIC 99.
03 WS-QQ PIC 99.

03 WS-MTH-MONTH OCCURS 12 TIMES.
05 WS-MTH-WEEK OCCURS 6 TIMES.
07 WS-DAY-FLD OCCURS 7 TIMES.
09 WS-DAY PIC ZZ.
01 INPDATE-RECORD.
05 INPD-YEAR PIC 9(04).
05 FILLER PIC X(01).
05 INPD-MONTH PIC 9(02).
05 FILLER PIC X(01).
05 INPD-DAY PIC 9(02).
01 WMS-DOW PIC 9(01).
01 WS-PRT PIC X(132).
01 WS-COL PIC 9(03) VALUE 0.
01 WS-PP PIC 9(03) VALUE 0.
01 WS-CFGN.
03 FILLER PIC 9(03) VALUE 80.
03 FILLER PIC 9(02) VALUE 5.
03 FILLER PIC 9(01) VALUE 1.
03 FILLER PIC 9(02) VALUE 5.
03 FILLER PIC 9(01) VALUE 2.
01 WS-CFGW.
03 FILLER PIC 9(03) VALUE 120.
03 FILLER PIC 9(02) VALUE 10.
03 FILLER PIC 9(01) VALUE 2.
03 FILLER PIC 9(02) VALUE 10.
03 FILLER PIC 9(01) VALUE 3.
01 WS-CFG.
03 WS-LS PIC 9(03) VALUE 120.
03 WS-LMAR PIC 9(02) VALUE 10.
03 WS-SPBD PIC 9(01) VALUE 2.
03 WS-SPBC PIC 9(02) VALUE 10.
03 WS-DNMW PIC 9(01) VALUE 3.
PROCEDURE DIVISION.
MOVE '1969-01-01' TO INPDATE-RECORD
MOVE WS-CFGN TO WS-CFG
IF (FUNCTION MOD ( INPD-YEAR , 400 ) = 0
OR (FUNCTION MOD ( INPD-YEAR , 4 ) = 0
AND
FUNCTION MOD ( INPD-YEAR , 100 ) NOT = 0))
MOVE 29 TO WS-MTH-INFO-DAYS (02)
ELSE
MOVE 28 TO WS-MTH-INFO-DAYS (02)
END-IF

PERFORM VARYING WS-MM FROM 1 BY +1
UNTIL WS-MM > 12
MOVE WS-MM TO INPD-MONTH
CALL 'DATE2DOW' USING INPDATE-RECORD, WMS-DOW
COMPUTE WS-MTH-DD = 1 - WMS-DOW
COMPUTE WS-DAYS = WS-MTH-INFO-DAYS (INPD-MONTH)
PERFORM VARYING WS-WK FROM 1 BY +1
UNTIL WS-WK > 6
PERFORM VARYING WS-DD FROM 1 BY +1
UNTIL WS-DD > 7
COMPUTE WS-MTH-DD = WS-MTH-DD + 1
IF (WS-MTH-DD < 1)
OR (WS-MTH-DD > WS-DAYS)
MOVE 0 TO WS-DAY (WS-MM, WS-WK, WS-DD)
ELSE
MOVE WS-MTH-DD TO WS-DAY (WS-MM, WS-WK, WS-DD)
END-IF
END-PERFORM
END-PERFORM
END-PERFORM

COMPUTE WS-MM = 0
PERFORM VARYING WS-QQ FROM 1 BY +1
UNTIL WS-QQ > 4

INITIALIZE WS-PRT
COMPUTE WS-PP = 1
PERFORM VARYING WS-COL FROM 1 BY +1
UNTIL WS-COL > 3
COMPUTE WS-MM = 3 * (WS-QQ - 1) + WS-COL

IF WS-COL = 1
COMPUTE WS-PP = WS-PP + WS-LMAR + 2 - WS-DNMW
ELSE
COMPUTE WS-PP = WS-PP + WS-SPBC + 2 - WS-DNMW
END-IF
MOVE WS-MTH-INFO-NAME (WS-MM)
TO WS-PRT(WS-PP:9)
COMPUTE WS-PP
= WS-PP + ( 2 * 7 + WS-SPBD * 6 + WS-SPBD - 1)
- 4
MOVE INPD-YEAR TO WS-PRT (WS-PP:4)
COMPUTE WS-PP = WS-PP + 4
END-PERFORM
DISPLAY WS-PRT (1:WS-LS)

INITIALIZE WS-PRT
COMPUTE WS-PP = 1
PERFORM VARYING WS-COL FROM 1 BY +1
UNTIL WS-COL > 3
COMPUTE WS-MM = 3 * (WS-QQ - 1) + WS-COL

IF WS-COL = 1
COMPUTE WS-PP = WS-PP + WS-LMAR + 2 - WS-DNMW
ELSE
COMPUTE WS-PP = WS-PP + WS-SPBC + 2 - WS-DNMW
END-IF
PERFORM VARYING WS-DD FROM 1 BY +1
UNTIL WS-DD > 7
IF WS-DD > 1
COMPUTE WS-PP = WS-PP + WS-SPBD + 2 - WS-DNMW
END-IF
MOVE WS-DAY-NAME (WS-DD) (1:WS-DNMW)
TO WS-PRT (WS-PP:WS-DNMW)
COMPUTE WS-PP = WS-PP + WS-DNMW
END-PERFORM
END-PERFORM
DISPLAY WS-PRT (1:WS-LS)

PERFORM VARYING WS-WK FROM 1 BY +1
UNTIL WS-WK > 6
INITIALIZE WS-PRT
COMPUTE WS-PP = 1
PERFORM VARYING WS-COL FROM 1 BY +1
UNTIL WS-COL > 3
COMPUTE WS-MM = 3 * (WS-QQ - 1) + WS-COL

IF WS-COL = 1
COMPUTE WS-PP = WS-PP + WS-LMAR
ELSE
COMPUTE WS-PP = WS-PP + WS-SPBC
END-IF
PERFORM VARYING WS-DD FROM 1 BY +1
UNTIL WS-DD > 7
IF WS-DD > 1
COMPUTE WS-PP = WS-PP + WS-SPBD
END-IF
MOVE WS-DAY (WS-MM, WS-WK, WS-DD)
TO WS-PRT (WS-PP:2)
COMPUTE WS-PP = WS-PP + 2
END-PERFORM
END-PERFORM
DISPLAY WS-PRT (1:WS-LS)
END-PERFORM
DISPLAY ' '
END-PERFORM
GOBACK
.
END PROGRAM CALEND.
IDENTIFICATION DIVISION.
PROGRAM-ID. DATE2DOW.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WMS-WORK-AREA.
03 WMS-YEAR PIC 9(04).
03 WMS-MONTH PIC 9(02).
03 WMS-CSYS PIC 9(01) VALUE 1.
03 WMS-SUM pic 9(04).
LINKAGE SECTION.
01 INPDATE-RECORD.
05 INPD-YEAR PIC 9(04).
05 FILLER PIC X(01).
05 INPD-MONTH PIC 9(02).
05 FILLER PIC X(01).
05 INPD-DAY PIC 9(02).
01 WMS-DOW PIC 9(01).
PROCEDURE DIVISION USING INPDATE-RECORD, WMS-DOW.
1010-CONVERT-DATE-TO-DOW.
IF INPD-MONTH < 3
COMPUTE WMS-MONTH = INPD-MONTH + 12
COMPUTE WMS-YEAR = INPD-YEAR - 1
ELSE
COMPUTE WMS-MONTH = INPD-MONTH
COMPUTE WMS-YEAR = INPD-YEAR
END-IF
COMPUTE WMS-SUM =
( INPD-DAY + 2 * WMS-MONTH + WMS-YEAR
+ FUNCTION INTEGER (6 * (WMS-MONTH + 1) / 10)
+ FUNCTION INTEGER ( WMS-YEAR / 4 )
- FUNCTION INTEGER ( WMS-YEAR / 100 )
+ FUNCTION INTEGER ( WMS-YEAR / 400 )
+ WMS-CSYS )
COMPUTE WMS-DOW = FUNCTION MOD (WMS-SUM, 7) + 1
GOBACK
.
END PROGRAM DATE2DOW.

Output (based on 80 character wide display)

JANUARY         1969     FEBRUARY        1969     MARCH           1969
SU MO TU WE TH FR SA     SU MO TU WE TH FR SA     SU MO TU WE TH FR SA
1  2  3  4                        1                        1
5  6  7  8  9 10 11      2  3  4  5  6  7  8      2  3  4  5  6  7  8
12 13 14 15 16 17 18      9 10 11 12 13 14 15      9 10 11 12 13 14 15
19 20 21 22 23 24 25     16 17 18 19 20 21 22     16 17 18 19 20 21 22
26 27 28 29 30 31        23 24 25 26 27 28        23 24 25 26 27 28 29
30 31

APRIL           1969     MAY             1969     JUNE            1969
SU MO TU WE TH FR SA     SU MO TU WE TH FR SA     SU MO TU WE TH FR SA
1  2  3  4  5                  1  2  3      1  2  3  4  5  6  7
6  7  8  9 10 11 12      4  5  6  7  8  9 10      8  9 10 11 12 13 14
13 14 15 16 17 18 19     11 12 13 14 15 16 17     15 16 17 18 19 20 21
20 21 22 23 24 25 26     18 19 20 21 22 23 24     22 23 24 25 26 27 28
27 28 29 30              25 26 27 28 29 30 31     29 30

JULY            1969     AUGUST          1969     SEPTEMBER       1969
SU MO TU WE TH FR SA     SU MO TU WE TH FR SA     SU MO TU WE TH FR SA
1  2  3  4  5                     1  2         1  2  3  4  5  6
6  7  8  9 10 11 12      3  4  5  6  7  8  9      7  8  9 10 11 12 13
13 14 15 16 17 18 19     10 11 12 13 14 15 16     14 15 16 17 18 19 20
20 21 22 23 24 25 26     17 18 19 20 21 22 23     21 22 23 24 25 26 27
27 28 29 30 31           24 25 26 27 28 29 30     28 29 30
31

OCTOBER         1969     NOVEMBER        1969     DECEMBER        1969
SU MO TU WE TH FR SA     SU MO TU WE TH FR SA     SU MO TU WE TH FR SA
1  2  3  4                        1         1  2  3  4  5  6
5  6  7  8  9 10 11      2  3  4  5  6  7  8      7  8  9 10 11 12 13
12 13 14 15 16 17 18      9 10 11 12 13 14 15     14 15 16 17 18 19 20
19 20 21 22 23 24 25     16 17 18 19 20 21 22     21 22 23 24 25 26 27
26 27 28 29 30 31        23 24 25 26 27 28 29     28 29 30 31
30

## Common Lisp

Depends on quicklisp.

(ql:quickload '(date-calc))

(defparameter *day-row* "Su Mo Tu We Th Fr Sa")
(defparameter *calendar-margin* 3)

(defun month-to-word (month)
"Translate a MONTH from 1 to 12 into its word representation."
(svref #("January" "February" "March" "April"
"May" "June" "July" "August"
"September" "October" "November" "December")
(1- month)))

(defun month-strings (year month)
"Collect all of the strings that make up a calendar for a given
MONTH and YEAR."

(,(date-calc:center (month-to-word month) (length *day-row*))
,*day-row*
;; We can assume that a month calendar will always fit into a 7 by 6 block
;; of values. This makes it easy to format the resulting strings.
,@ (let ((days (make-array (* 7 6) :initial-element nil)))
(loop :for i :from (date-calc:day-of-week year month 1)
:for day :from 1 :to (date-calc:days-in-month year month)
:do (setf (aref days i) day))
(loop :for i :from 0 :to 5
:collect
(format nil "~{~:[ ~;~2,d~]~^ ~}"
(loop :for day :across (subseq days (* i 7) (+ 7 (* i 7)))
:append (if day (list day day) (list day))))))))

(defun calc-columns (characters margin-size)
"Calculate the number of columns given the number of CHARACTERS per
column and the MARGIN-SIZE between them."

(multiple-value-bind (cols excess)
(truncate characters (+ margin-size (length *day-row*)))
(incf excess margin-size)
(if (>= excess (length *day-row*))
(1+ cols)
cols)))

(defun take (n list)
"Take the first N elements of a LIST."
(loop :repeat n :for x :in list :collect x))

(defun drop (n list)
"Drop the first N elements of a LIST."
(cond ((or (<= n 0) (null list)) list)
(t (drop (1- n) (cdr list)))))

(defun chunks-of (n list)
"Split the LIST into chunks of size N."
(assert (> n 0))
(loop :for x := list :then (drop n x)
:while x
:collect (take n x)))

(defun print-calendar (year &key (characters 80) (margin-size 3))
"Print out the calendar for a given YEAR, optionally specifying
a width limit in CHARACTERS and MARGIN-SIZE between months."

(assert (>= characters (length *day-row*)))
(assert (>= margin-size 0))
(let* ((calendars (loop :for month :from 1 :to 12
:collect (month-strings year month)))
(column-count (calc-columns characters margin-size))
(total-size (+ (* column-count (length *day-row*))
(* (1- column-count) margin-size)))
(format-string (concatenate 'string
"~{~a~^~" (write-to-string margin-size) ",0@T~}~%")))
(format t "~a~%~a~%~%"
(date-calc:center "[Snoopy]" total-size)
(date-calc:center (write-to-string year) total-size))
(loop :for row :in (chunks-of column-count calendars)
:do (apply 'mapcar
(lambda (&rest heads)
(format t format-string heads))
row))))
Output:
CL-USER> (print-calendar 1969)
[Snoopy]
1969

January                February                March
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4                      1                      1
5  6  7  8  9 10 11    2  3  4  5  6  7  8    2  3  4  5  6  7  8
12 13 14 15 16 17 18    9 10 11 12 13 14 15    9 10 11 12 13 14 15
19 20 21 22 23 24 25   16 17 18 19 20 21 22   16 17 18 19 20 21 22
26 27 28 29 30 31      23 24 25 26 27 28      23 24 25 26 27 28 29
30 31
April                   May                    June
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5                1  2  3
6  7  8  9 10 11 12    4  5  6  7  8  9 10    1  2  3  4  5  6  7
13 14 15 16 17 18 19   11 12 13 14 15 16 17    8  9 10 11 12 13 14
20 21 22 23 24 25 26   18 19 20 21 22 23 24   15 16 17 18 19 20 21
27 28 29 30            25 26 27 28 29 30 31   22 23 24 25 26 27 28
29 30
July                  August               September
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5                   1  2       1  2  3  4  5  6
6  7  8  9 10 11 12    3  4  5  6  7  8  9    7  8  9 10 11 12 13
13 14 15 16 17 18 19   10 11 12 13 14 15 16   14 15 16 17 18 19 20
20 21 22 23 24 25 26   17 18 19 20 21 22 23   21 22 23 24 25 26 27
27 28 29 30 31         24 25 26 27 28 29 30   28 29 30
31
October                November               December
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4                      1       1  2  3  4  5  6
5  6  7  8  9 10 11    2  3  4  5  6  7  8    7  8  9 10 11 12 13
12 13 14 15 16 17 18    9 10 11 12 13 14 15   14 15 16 17 18 19 20
19 20 21 22 23 24 25   16 17 18 19 20 21 22   21 22 23 24 25 26 27
26 27 28 29 30 31      23 24 25 26 27 28 29   28 29 30 31
30
NIL

## D

import std.stdio, std.datetime, std.string, std.conv;

void printCalendar(in uint year, in uint nCols)
in {
assert(nCols > 0 && nCols <= 12);
} body {
immutable rows = 12 / nCols + (12 % nCols != 0);
auto date = Date(year, 1, 1);
int offs = date.dayOfWeek;
const months = "January February March April May June
July August September October November December"
.split;

string[8][12] mons;
foreach (immutable m; 0 .. 12) {
mons[m][0] = months[m].center(21);
mons[m][1] = " Su Mo Tu We Th Fr Sa";
immutable dim = date.daysInMonth;
foreach (immutable d; 1 .. 43) {
immutable day = d > offs && d <= offs + dim;
immutable str = day ? format(" %2s", d-offs) : " ";
mons[m][2 + (d - 1) / 7] ~= str;
}
offs = (offs + dim) % 7;
date.add!"months"(1);
}

"[Snoopy Picture]".center(nCols * 24 + 4).writeln;
writeln(year.text.center(nCols * 24 + 4), "\n");
foreach (immutable r; 0 .. rows) {
string[8] s;
foreach (immutable c; 0 .. nCols) {
if (r * nCols + c > 11)
break;
foreach (immutable i, line; mons[r * nCols + c])
s[i] ~= format("  %s", line);
}
writefln("%-(%s\n%)\n", s);
}
}

void main() {
printCalendar(1969, 3);
}
[Snoopy Picture]
1969

January                February                  March
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1                       1
5  6  7  8  9 10 11     2  3  4  5  6  7  8     2  3  4  5  6  7  8
12 13 14 15 16 17 18     9 10 11 12 13 14 15     9 10 11 12 13 14 15
19 20 21 22 23 24 25    16 17 18 19 20 21 22    16 17 18 19 20 21 22
26 27 28 29 30 31       23 24 25 26 27 28       23 24 25 26 27 28 29
30 31

April                    May                    June
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                 1  2  3     1  2  3  4  5  6  7
6  7  8  9 10 11 12     4  5  6  7  8  9 10     8  9 10 11 12 13 14
13 14 15 16 17 18 19    11 12 13 14 15 16 17    15 16 17 18 19 20 21
20 21 22 23 24 25 26    18 19 20 21 22 23 24    22 23 24 25 26 27 28
27 28 29 30             25 26 27 28 29 30 31    29 30

July                   August                 September
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4  5                    1  2        1  2  3  4  5  6
6  7  8  9 10 11 12     3  4  5  6  7  8  9     7  8  9 10 11 12 13
13 14 15 16 17 18 19    10 11 12 13 14 15 16    14 15 16 17 18 19 20
20 21 22 23 24 25 26    17 18 19 20 21 22 23    21 22 23 24 25 26 27
27 28 29 30 31          24 25 26 27 28 29 30    28 29 30
31

October                November                December
Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa    Su Mo Tu We Th Fr Sa
1  2  3  4                       1        1  2  3  4  5  6
5  6  7  8  9 10 11     2  3  4  5  6  7  8     7  8  9 10 11 12 13
12 13 14 15 16 17 18     9 10 11 12 13 14 15    14 15 16 17 18 19 20
19 20 21 22 23 24 25    16 17 18 19 20 21 22    21 22 23 24 25 26 27
26 27 28 29 30 31       23 24 25 26 27 28 29    28 29 30 31
30

## Fortran

Already having a routine to produce a calendar simplified matters. However, it added to each row of days a row of annotations for those days (Xmas, etc. and also +2hh and -2hh for the days with two half-hour changes in length due to daylight saving: NZ also had daylight saving with changes of one half-hour) which meant that the field allowance was always four. With the annotations abandoned, this could be reduced to three, and, the first day column on a line does not need a leading space. Since the method employed variables for the layout, it could easily be twiddled to have three months per line (thus fitting into a line length of 80) or six (using most of a line length of 132) and so it became a matter of pulling together the needed routines from various places.

MODULE DATEGNASH !Assorted vexations. Time and calendar games, with local flavourings added.

TYPE DateBag !Pack three parts into one.
INTEGER DAY,MONTH,YEAR !The usual suspects.
END TYPE DateBag !Simple enough.

CHARACTER*9 MONTHNAME(12),DAYNAME(0:6) !Re-interpretations.
PARAMETER (MONTHNAME = (/"January","February","March","April",
1 "May","June","July","August","September","October","November",
2 "December"/))
PARAMETER (DAYNAME = (/"Sunday","Monday","Tuesday","Wednesday",
1 "Thursday","Friday","Saturday"/)) !Index this array with DayNum mod 7.
CHARACTER*3 MTHNAME(12) !The standard abbreviations.
PARAMETER (MTHNAME = (/"JAN","FEB","MAR","APR","MAY","JUN",
1 "JUL","AUG","SEP","OCT","NOV","DEC"/))

INTEGER*4 JDAYSHIFT !INTEGER*2 just isn't enough.
PARAMETER (JDAYSHIFT = 2415020) !Thus shall 31/12/1899 give 0, a Sunday, via DAYNUM.
CONTAINS
INTEGER FUNCTION LSTNB(TEXT) !Sigh. Last Not Blank.
Concocted yet again by R.N.McLean (whom God preserve) December MM.
Code checking reveals that the Compaq compiler generates a copy of the string and then finds the length of that when using the latter-day intrinsic LEN_TRIM. Madness!
Can't DO WHILE (L.GT.0 .AND. TEXT(L:L).LE.' ') !Control chars. regarded as spaces.
Curse the morons who think it good that the compiler MIGHT evaluate logical expressions fully.
Crude GO TO rather than a DO-loop, because compilers use a loop counter as well as updating the index variable.
Comparison runs of GNASH showed a saving of ~3% in its mass-data reading through the avoidance of DO in LSTNB alone.
Crappy code for character comparison of varying lengths is avoided by using ICHAR which is for single characters only.
Checking the indexing of CHARACTER variables for bounds evoked astounding stupidities, such as calculating the length of TEXT(L:L) by subtracting L from L!
Comparison runs of GNASH showed a saving of ~25-30% in its mass data scanning for this, involving all its two-dozen or so single-character comparisons, not just in LSTNB.
CHARACTER*(*),INTENT(IN):: TEXT !The bumf. If there must be copy-in, at least there need not be copy back.
INTEGER L !The length of the bumf.
L = LEN(TEXT) !So, what is it?
1 IF (L.LE.0) GO TO 2 !Are we there yet?
IF (ICHAR(TEXT(L:L)).GT.ICHAR(" ")) GO TO 2 !Control chars are regarded as spaces also.
L = L - 1 !Step back one.
GO TO 1 !And try again.
2 LSTNB = L !The last non-blank, possibly zero.
RETURN !Unsafe to use LSTNB as a variable.
END FUNCTION LSTNB !Compilers can bungle it.
CHARACTER*2 FUNCTION I2FMT(N) !These are all the same.
INTEGER*4 N !But, the compiler doesn't offer generalisations.
IF (N.LT.0) THEN !Negative numbers cop a sign.
IF (N.LT.-9) THEN !But there's not much room left.
I2FMT = "-!" !So this means 'overflow'.
ELSE !Otherwise, room for one negative digit.
I2FMT = "-"//CHAR(ICHAR("0") - N) !Thus. Presume adjacent character codes, etc.
END IF !So much for negative numbers.
ELSE IF (N.LT.10) THEN !Single digit positive?
I2FMT = " " //CHAR(ICHAR("0") + N) !Yes. This.
ELSE IF (N.LT.100) THEN !Two digit positive?
I2FMT = CHAR(N/10 + ICHAR("0")) !Yes.
1 //CHAR(MOD(N,10) + ICHAR("0")) !These.
ELSE !Otherwise,
I2FMT = "+!" !Positive overflow.
END IF !So much for that.
END FUNCTION I2FMT !No WRITE and FORMAT unlimbering.
CHARACTER*8 FUNCTION I8FMT(N) !Oh for proper strings.
INTEGER*4 N
CHARACTER*8 HIC
WRITE (HIC,1) N
1 FORMAT (I8)
I8FMT = HIC
END FUNCTION I8FMT

SUBROUTINE SAY(OUT,TEXT) !Gutted version that maintains no file logging output, etc.
INTEGER OUT
CHARACTER*(*) TEXT
WRITE (6,1) TEXT(1:LSTNB(TEXT))
1 FORMAT (A)
END SUBROUTINE SAY

INTEGER*4 FUNCTION DAYNUM(YY,M,D) !Computes (JDayN - JDayShift), not JDayN.
C Conversion from a Gregorian calendar date to a Julian day number, JDayN.
C Valid for any Gregorian calendar date producing a Julian day number
C greater than zero, though remember that the Gregorian calendar
C was not used before y1582m10d15 and often, not after that either.
C thus in England (et al) when Wednesday 2'nd September 1752 (Julian style)
C was followed by Thursday the 14'th, occasioning the Eleven Day riots
C because creditors demanded a full month's payment instead of 19/30'ths.
C The zero of the Julian day number corresponds to the first of January
C 4713BC on the *Julian* calendar's naming scheme, as extended backwards
C with current usage into epochs when it did not exist: the proleptic Julian calendar.
c This function employs the naming scheme of the *Gregorian* calendar,
c and if extended backwards into epochs when it did not exist (thus the
c proleptic Gregorian calendar) it would compute a zero for y-4713m11d24 *if*
c it is supposed there was a year zero between 1BC and 1AD (as is convenient
c for modern mathematics and astronomers and their simple calculations), *but*
c 1BC immediately preceeds 1AD without any year zero in between (and is a leap year)
c thus the adjustment below so that the date is y-4714m11d24 or 4714BCm11d24,
c not that this name was in use at the time...
c Although the Julian calendar (introduced by himself in what we would call 45BC,
c which was what the Romans occasionally called 709AUC) was provoked by the
c "years of confusion" resulting from arbitrary application of the rules
c for the existing Roman calendar, other confusions remain unresolved,
c so precise dating remains uncertain despite apparently precise specifications
c (and much later, Dennis the Short chose wrongly for the birth of Christ)
c and the Roman practice of inclusive reckoning meant that every four years
c was interpreted as every third (by our exclusive reckoning) so that the
c leap years were not as we now interpret them. This was resolved by Augustus
c but exactly when (and what date name is assigned) and whose writings used
c which system at the time of writing is a matter of more confusion,
c and this has continued for centuries.
C Accordingly, although an algorithm may give a regular sequence of date names,
c that does not mean that those date names were used at the time even if the
c calendar existed then, because the interpretation of the algorithm varied.
c This in turn means that a date given as being on the Julian calendar
c prior to about 10AD is not as definite as it may appear and its alignment
c with the astronomical day number is uncertain even though the calculation
c is quite definite.
c
C Computationally, year 1 is preceded by year 0, in a smooth progression.
C But there was never a year zero despite what astronomers like to say,
C so the formula's year 0 corresponds to 1BC, year -1 to 2BC, and so on back.
C Thus y-4713 in this counting would be 4714BC on the Gregorian calendar,
C were it to have existed then which it didn't.
C To conform to the civil usage, the incoming YY, presumed a proper BC (negative)
C and AD (positive) year is converted into the computational counting sequence, Y,
C and used in the formula. If a YY = 0 is (improperly) offered, it will manifest
C as 1AD. Thus YY = -4714 will lead to calculations with Y = -4713.
C Thus, 1BC is a leap year on the proleptic Gregorian calendar.
C For their convenience, astronomers decreed that a day starts at noon, so that
C in Europe, observations through the night all have the same day number.
C The current Western civil calendar however has the day starting just after midnight
C and that day's number lasts until the following midnight.
C
C There is no constraint on the values of D, which is just added as it stands.
C This means that if D = 0, the daynumber will be that of the last day of the
C previous month. Likewise, M = 0 or M = 13 will wrap around so that Y,M + 1,0
C will give the last day of month M (whatever its length) as one day before
C the first day of the next month.
C
C Example: Y = 1970, M = 1, D = 1; JDAYN = 2440588, a Thursday but MOD(2440588,7) = 3.
C and with the adjustment JDAYSHIFT, DAYNUM = 25568; mod 7 = 4 and DAYNAME(4) = "Thursday".
C The Julian Day number 2440588.0 is for NOON that Thursday, 2440588.5 is twelve hours later.
C And Julian Day number 2440587.625 is for three a.m. Thursday.
C
C DAYNUM and MUNYAD are the infamous routines of H. F. Fliegel and T.C. van Flandern,
C presented in Communications of the ACM, Vol. 11, No. 10 (October, 1968).
Carefully typed in again by R.N.McLean (whom God preserve) December XXMMIIX.
C Though I remain puzzled as to why they used I,J,K for Y,M,D,
C given that the variables were named in the INTEGER statement anyway.
INTEGER*4 JDAYN !Without rebasing, this won't fit in INTEGER*2.
INTEGER YY,Y,M,MM,D !NB! Full year number, so 1970, not 70.
Caution: integer division in Fortran does not produce fractional results.
C The fractional part is discarded so that 4/3 gives 1 and -4/3 gives -1.
C Thus 4/3 might be Trunc(4/3) or 4 div 3 in other languages. Beware of negative numbers!
Y = YY !I can fiddle this copy without damaging the original's value.
IF (Y.LT.1) Y = Y + 1 !Thus YY = -2=2BC, -1=1BC, +1=1AD, ... becomes Y = -1, 0, 1, ...
MM = (M - 14)/12 !Calculate once. Note that this is integer division, truncating.
JDAYN = D - 32075 !This is the proper astronomer's Julian Day Number.
a + 1461*(Y + 4800 + MM)/4
b + 367*(M - 2 - MM*12)/12
c - 3*((Y + 4900 + MM)/100)/4
DAYNUM = JDAYN - JDAYSHIFT !Thus, *NOT* the actual *Julian* Day Number.
END FUNCTION DAYNUM !But one such that Mod(n,7) gives day names.

Could compute the day of the year somewhat as follows...
c DN:=D + (61*Month + (Month div 8)) div 2 - 30
c + if Month > 2 then FebLength - 30 else 0;

TYPE(DATEBAG) FUNCTION MUNYAD(DAYNUM) !Oh for palindromic programming!
Conversion from a Julian day number to a Gregorian calendar date. See JDAYN/DAYNUM.
INTEGER*4 DAYNUM,JDAYN !Without rebasing, this won't fit in INTEGER*2.
INTEGER Y,M,D,L,N !Y will be a full year number: 1950 not 50.
JDAYN = DAYNUM + JDAYSHIFT !Revert to a proper Julian day number.
L = JDAYN + 68569 !Further machinations of H. F. Fliegel and T.C. van Flandern.
N = 4*L/146097
L = L - (146097*N + 3)/4
Y = 4000*(L + 1)/1461001
L = L - 1461*Y/4 + 31
M = 80*L/2447
D = L - 2447*M/80
L = M/11
M = M + 2 - 12*L
Y = 100*(N - 49) + Y + L
IF (Y.LT.1) Y = Y - 1 !The other side of conformity to BC/AD, as in DAYNUM.
MUNYAD%YEAR = Y !Now place for the world to see.
MUNYAD%MONTH = M
MUNYAD%DAY = D
END FUNCTION MUNYAD !A year has 365.2421988 days...

INTEGER FUNCTION PMOD(N,M) !Remainder, mod M; always positive even if N is negative.
c For date calculations, the MOD function is expected to yield positive remainders,
c in line with the idea that MOD(a,b) = MOD(a ± b,b) as is involved in shifting the zero
c of the daynumber count by a multiple of seven when considering the day of the week.
c For this reason, the zero day was chosen to be 31/12/1899, a Sunday, so that all
c day numbers would be positive. But, there was generation at Reefton in 1886.
c For some computers, the positive interpretation is implemented, for others, not.
c In the case MOD(N,M) = N - Truncate(N/M)*M, MOD(-6,7) = -6 even though MOD(1,7) = 1.
INTEGER N,M !The numbers. M presumed positive.
PMOD = MOD(MOD(N,M) + M,M) !Double do does de deed.
END FUNCTION PMOD !Simple enough.

SUBROUTINE CALENDAR(Y1,Y2,COLUMNS) !Print a calendar, with holiday annotations.
Careful with the MOD function. MOD(-6,7) may be negative on some systems, positive on others. Thus, PMOD.
INTEGER Y1,Y2,YEAR !Ah yes. Year stuff.
INTEGER M,M1,M2,MONTH !And within each year are the months.
INTEGER*4 DN1,DN2,DN,D !But days are handled via day numbers.
INTEGER W,G !Layout: width and gap.
INTEGER L,LINE !Vertical layout.
INTEGER COL,COLUMNS,COLWIDTH !Horizontal layout.
INTEGER CODE !Days are not all alike.
CHARACTER*200 STRIPE(6),SPECIAL(6),MLINE,DLINE !Scratchpads.
IF (Y1.LE.0) CALL SAY(MSG,"Despite the insinuations of "
1 //"astronomers seduced by the ease of their arithmetic, "
2 //"there is no year zero. 1AD is preceded by 1BC, "
3 //"corresponding to year -1, 2BC to year -2, etc.")
IF (Y1.LT.1582) CALL SAY(MSG,"This Gregorian calendar"
1 //" scheme did not exist prior to 1582.")
c COLUMNS = 4 !Number of months across the page.
c W = 4 !Width of a day's field.
c G = 3 !Added gap between month columns.
W = 3 !Abandon the annotation of the day's class, so just a space and two digits.
G = 1 !Set the gap to one.
COLWIDTH = 7*W + G !Seven days to a week, plus a gap.
Y:DO YEAR = Y1,Y2 !Step through the years.
CALL SAY(MSG,"") !Space out between each year's schedule.
IF (YEAR.EQ.0) THEN !This year number is improper.
CALL SAY(MSG,"There is no year zero.") !Declare correctness.
CYCLE Y !Skip this year.
END IF !Otherwise, no evasions.
MLINE = "" !Prepare a field..
L = (COLUMNS*COLWIDTH - G - 8)/2 !Find the centre.
IF (YEAR.GT.0) THEN !Ordinary Anno Domine years?
MLINE(L:) = I8FMT(YEAR) !Yes. Place the year number.
ELSE !Otherwise, we're in BC.
MLINE(L - 1:) = I8FMT(-YEAR)//"BC" !There is no year zero.
END IF !So much for year games.
CALL SAY(MSG,MLINE) !Splot the year.
DO MONTH = 1,12,COLUMNS !Step through the months of this YEAR.
M1 = MONTH !The first of this lot.
M2 = MIN(12,M1 + COLUMNS - 1) !The last.
MLINE = "" !Scrub the month names.
DLINE = "" !Wipe the day names in case COLUMNS does not divide 12.
STRIPE = "" !Scrub the day table.
SPECIAL = "" !And the associated special day remarks.
c L0 = W - 1 !Locate the first day number's first column.
L0 = 1 !Cram: no space in front of the Sunday day-of-the-month.
DO M = M1,M2 !Work through the months.
L = (COLWIDTH - G - LSTNB(MONTHNAME(M)))/2 - 1 !Centre the month name.
MLINE(L0 + L:) = MONTHNAME(M) !Splot.
DO D = 0,6 !Prepare this month's day name heading.
L = L0 + (3 - W) + D*W !Locate its first column.
DLINE(L:L + 2) = DAYNAME(D)(1:W - 1) !Squish.
END DO !On to the next day.
DN1 = DAYNUM(YEAR,M,1) !Day number of the first day of the month.
DN2 = DAYNUM(YEAR,M + 1,0)!Thus the last, without annoyance.
COL = MOD(PMOD(DN1,7) + 7,7) !What day of the week is the first day?
LINE = 1 !Whichever it is, it is on the first line.
D = 1 !Day of the month, not number of the day.
DO DN = DN1,DN2 !Step through the day numbers of this month.
L = L0 + COL*W !Finger the starting column.
STRIPE(LINE)(L:L + 1) = I2FMT(D) !Place the two-digit day number.
D = D + 1 !Advance to the next day of the current month
COL = COL + 1 !So, one more day along in the week.
IF (COL.GT.6) THEN !A fresh week is needed?
LINE = LINE + 1 !Yes.
COL = 0 !Start the new week.
END IF !So much for the end of a week.
END DO !On to the next day of this month.
L0 = L0 + 7*W + G !Locate the start column of the next month's column.
END DO !On to the next month in this layer.
CALL SAY(MSG,MLINE) !Name the months.
C CALL SAY(MSG,"") !Set off.
CALL SAY(MSG,DLINE) !Give the day name headings.
DO LINE = 1,6 !Now roll the day number table.
IF (STRIPE(LINE).NE."") THEN !Perhaps there was no use of the sixth line.
CALL SAY(MSG,STRIPE(LINE)) !Ah well. Show the day numbers.
END IF !So much for that week line.
END DO !On to the next week line.
END DO !On to the next batch of months of the YEAR.
END DO Y !On to the next YEAR.
CALL SAY(MSG,"") !Take a breath.
END SUBROUTINE CALENDAR !Enough of this.
END MODULE DATEGNASH !An ad-hoc assemblage.

PROGRAM SHOW1968 !Put it to the test.
USE DATEGNASH
INTEGER NCOL
DO NCOL = 1,6
CALL CALENDAR(1969,1969,NCOL)
END DO
END

Selected output, lacking alas the outbursts from Snoopy: three months /line

1969
January              February                March
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1                     1
5  6  7  8  9 10 11   2  3  4  5  6  7  8   2  3  4  5  6  7  8
12 13 14 15 16 17 18   9 10 11 12 13 14 15   9 10 11 12 13 14 15
19 20 21 22 23 24 25  16 17 18 19 20 21 22  16 17 18 19 20 21 22
26 27 28 29 30 31     23 24 25 26 27 28     23 24 25 26 27 28 29
30 31
April                  May                  June
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5               1  2  3   1  2  3  4  5  6  7
6  7  8  9 10 11 12   4  5  6  7  8  9 10   8  9 10 11 12 13 14
13 14 15 16 17 18 19  11 12 13 14 15 16 17  15 16 17 18 19 20 21
20 21 22 23 24 25 26  18 19 20 21 22 23 24  22 23 24 25 26 27 28
27 28 29 30           25 26 27 28 29 30 31  29 30
July                 August               September
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5                  1  2      1  2  3  4  5  6
6  7  8  9 10 11 12   3  4  5  6  7  8  9   7  8  9 10 11 12 13
13 14 15 16 17 18 19  10 11 12 13 14 15 16  14 15 16 17 18 19 20
20 21 22 23 24 25 26  17 18 19 20 21 22 23  21 22 23 24 25 26 27
27 28 29 30 31        24 25 26 27 28 29 30  28 29 30
31
October              November              December
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1      1  2  3  4  5  6
5  6  7  8  9 10 11   2  3  4  5  6  7  8   7  8  9 10 11 12 13
12 13 14 15 16 17 18   9 10 11 12 13 14 15  14 15 16 17 18 19 20
19 20 21 22 23 24 25  16 17 18 19 20 21 22  21 22 23 24 25 26 27
26 27 28 29 30 31     23 24 25 26 27 28 29  28 29 30 31
30

And with six...

1969
January              February                March                 April                  May                  June
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1                     1         1  2  3  4  5               1  2  3   1  2  3  4  5  6  7
5  6  7  8  9 10 11   2  3  4  5  6  7  8   2  3  4  5  6  7  8   6  7  8  9 10 11 12   4  5  6  7  8  9 10   8  9 10 11 12 13 14
12 13 14 15 16 17 18   9 10 11 12 13 14 15   9 10 11 12 13 14 15  13 14 15 16 17 18 19  11 12 13 14 15 16 17  15 16 17 18 19 20 21
19 20 21 22 23 24 25  16 17 18 19 20 21 22  16 17 18 19 20 21 22  20 21 22 23 24 25 26  18 19 20 21 22 23 24  22 23 24 25 26 27 28
26 27 28 29 30 31     23 24 25 26 27 28     23 24 25 26 27 28 29  27 28 29 30           25 26 27 28 29 30 31  29 30
30 31
July                 August               September              October              November              December
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5                  1  2      1  2  3  4  5  6            1  2  3  4                     1      1  2  3  4  5  6
6  7  8  9 10 11 12   3  4  5  6  7  8  9   7  8  9 10 11 12 13   5  6  7  8  9 10 11   2  3  4  5  6  7  8   7  8  9 10 11 12 13
13 14 15 16 17 18 19  10 11 12 13 14 15 16  14 15 16 17 18 19 20  12 13 14 15 16 17 18   9 10 11 12 13 14 15  14 15 16 17 18 19 20
20 21 22 23 24 25 26  17 18 19 20 21 22 23  21 22 23 24 25 26 27  19 20 21 22 23 24 25  16 17 18 19 20 21 22  21 22 23 24 25 26 27
27 28 29 30 31        24 25 26 27 28 29 30  28 29 30              26 27 28 29 30 31     23 24 25 26 27 28 29  28 29 30 31
31                                                                30

## Haskell

import qualified Data.Text as T
import Data.Time
import Data.Time.Calendar
import Data.Time.Calendar.WeekDate
import Data.List.Split (chunksOf)
import Data.List

data Day = Su | Mo | Tu | We | Th | Fr | Sa
deriving (Show, Eq, Ord, Enum)

data Month = January | February | March
| April | May | June
| July | August | September
| October | November | December
deriving (Show, Eq, Ord, Enum)

monthToInt :: Month -> Int
monthToInt = (+ 1) . fromEnum

dayFromDate :: Integer -> Month -> Int -> Int
dayFromDate year month day = day' mod 7
where (_, _, day'
) = toWeekDate $fromGregorian year (monthToInt month) day nSpaces :: Int -> T.Text nSpaces n = T.replicate n (T.pack " ") space :: T.Text space = nSpaces 1 calMarginWidth = 3 calMargin :: T.Text calMargin = nSpaces calMarginWidth calWidth = 20 listMonth :: Integer -> Month -> [T.Text] listMonth year month = [monthHeader, weekHeader] ++ weeks' where monthHeader = (T.center calWidth ' ') . T.pack$ show month

weekHeader = (T.intercalate space) $map (T.pack . show) [(Su)..] monthLength = toInteger$
gregorianMonthLength year $monthToInt month firstDay = dayFromDate year month 1 days = replicate firstDay (nSpaces 2) ++ map ((T.justifyRight 2 ' ') . T.pack . show) [1..monthLength] weeks = map (T.justifyLeft calWidth ' ')$
map (T.intercalate space) $chunksOf 7 days weeks' = weeks ++ replicate (6 - length weeks) (nSpaces calWidth) listCalendar :: Integer -> Int -> [[[T.Text]]] listCalendar year calColumns = (chunksOf calColumns) . (map (listMonth year))$
enumFrom January

calColFromCol :: Int -> Int
calColFromCol columns = c + if r >= calWidth then 1 else 0
where (c, r) = columns divMod (calWidth + calMarginWidth)

colFromCalCol :: Int -> Int
colFromCalCol calCol = calCol * calWidth + ((calCol - 1) * calMarginWidth)

center :: Int -> String -> String
center i a = T.unpack . (T.center i ' ') $T.pack a printCal :: [[[T.Text]]] -> IO () printCal [] = return () printCal (c:cx) = do mapM_ (putStrLn . T.unpack) rows printCal cx where rows = map (T.intercalate calMargin)$ transpose c

printCalendar :: Integer -> Int -> IO ()
printCalendar year columns =
if columns < 20
then putStrLn $"Cannot print less than 20 columns" else do putStrLn$ center columns' "[Maybe Snoopy]"
putStrLn $center columns'$ show year
putStrLn ""
printCal listCalendar year calcol' where calcol' = calColFromCol columns columns' = colFromCalCol calcol' *Main> printCalendar 1969 80 [Maybe Snoopy] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 ## Icon and Unicon The procedures printCalendar handles formatting of large components and uses co-expressions to keep the formatting of week elements in each column synchronized. The procedure CalendarFormatWeek is a generator that returns heading elements, alignment spacing, and individual days. procedure main(A) printCalendar(\A[1]|1969) end procedure printCalendar(year) #: Print a 3 column x 80 char calendar cols := 3 # fixed width mons := [] # table of months "January February March April May June " || "July August September October November December " ? while put(mons, tab(find(" "))) do move(1) write(center("[Snoopy Picture]",cols * 24 + 4)) # mandatory .. write(center(year,cols * 24 + 4), "\n") # ... headers M := list(cols) # coexpr container every mon := 0 to 9 by cols do { # go through months by cols writes(" ") every i := 1 to cols do { writes(center(mons[mon+i],24)) # header months M[i] := create CalendarFormatWeek(1969,mon + i) # formatting coexpr } write() every 1 to 7 do { # 1 to max rows every c := 1 to cols do { # for each column writes(" ") every 1 to 7 do writes(right(@M[c],3)) # each row day element } write() } } end link datetime procedure CalendarFormatWeek(year,m) #: Format Week for Calendar static D initial D := [31,28,31,30,31,30,31,31,30,31,30,31] every suspend "Su"|"Mo"|"Tu"|"We"|"Th"|"Fr"|"Sa" # header every 1 to (d := (julian(m,1,year)+1)%7) do suspend "" # lead day alignment every suspend 1 to D[m] do d +:= 1 # days if m = 2 & IsLeapYear(year) then suspend (d +:= 1, 29) # LY adjustment every d to (6*7) do suspend "" # trailer alignment end Output: [Snoopy Picture] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 ## J Solution: require 'dates format' NB. J6.x require 'dates general/misc/format' NB. J7.x calBody=: (1 1 }. _1 _1 }. ":)@(-@(<.@%&22)@[ ]\ calendar@]) calTitle=: (<: - 22&|)@[ center '[Insert Snoopy here]' , '' ,:~ ":@] formatCalendar=: calTitle , calBody Example use: 80 formatCalendar 1969 [Insert Snoopy here] 1969 Jan │ Feb │ Mar Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa 1 2 3 411 5 6 7 8 9 10 112 3 4 5 6 7 82 3 4 5 6 7 8 12 13 14 15 16 17 189 10 11 12 13 14 159 10 11 12 13 14 15 19 20 21 22 23 24 2516 17 18 19 20 21 2216 17 18 19 20 21 22 26 27 28 29 30 3123 24 25 26 27 2823 24 25 26 27 28 29 │ │ 30 31 ─────────────────────┼─────────────────────┼───────────────────── Apr │ May │ Jun Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa 1 2 3 4 51 2 31 2 3 4 5 6 7 6 7 8 9 10 11 124 5 6 7 8 9 108 9 10 11 12 13 14 13 14 15 16 17 18 1911 12 13 14 15 16 1715 16 17 18 19 20 21 20 21 22 23 24 25 2618 19 20 21 22 23 2422 23 24 25 26 27 28 27 28 29 3025 26 27 28 29 30 3129 30 │ │ ─────────────────────┼─────────────────────┼───────────────────── Jul │ Aug │ Sep Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa 1 2 3 4 51 21 2 3 4 5 6 6 7 8 9 10 11 123 4 5 6 7 8 97 8 9 10 11 12 13 13 14 15 16 17 18 1910 11 12 13 14 15 1614 15 16 17 18 19 20 20 21 22 23 24 25 2617 18 19 20 21 22 2321 22 23 24 25 26 27 27 28 29 30 3124 25 26 27 28 29 3028 29 30 31 ─────────────────────┼─────────────────────┼───────────────────── Oct │ Nov │ Dec Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa│ Su Mo Tu We Th Fr Sa 1 2 3 411 2 3 4 5 6 5 6 7 8 9 10 112 3 4 5 6 7 87 8 9 10 11 12 13 12 13 14 15 16 17 189 10 11 12 13 14 1514 15 16 17 18 19 20 19 20 21 22 23 24 2516 17 18 19 20 21 2221 22 23 24 25 26 27 26 27 28 29 30 3123 24 25 26 27 28 2928 29 30 31 30 ## Java Translation of: D import java.text.*; import java.util.*; public class CalendarTask { public static void main(String[] args) { printCalendar(1969, 3); } static void printCalendar(int year, int nCols) { if (nCols < 1 || nCols > 12) throw new IllegalArgumentException("Illegal column width."); Calendar date = new GregorianCalendar(year, 0, 1); int nRows = (int) Math.ceil(12.0 / nCols); int offs = date.get(Calendar.DAY_OF_WEEK) - 1; int w = nCols * 24; String[] monthNames = new DateFormatSymbols(Locale.US).getMonths(); String[][] mons = new String[12][8]; for (int m = 0; m < 12; m++) { String name = monthNames[m]; int len = 11 + name.length() / 2; String format = MessageFormat.format("%{0}s%{1}s", len, 21 - len); mons[m][0] = String.format(format, name, ""); mons[m][1] = " Su Mo Tu We Th Fr Sa"; int dim = date.getActualMaximum(Calendar.DAY_OF_MONTH); for (int d = 1; d < 43; d++) { boolean isDay = d > offs && d <= offs + dim; String entry = isDay ? String.format(" %2s", d - offs) : " "; if (d % 7 == 1) mons[m][2 + (d - 1) / 7] = entry; else mons[m][2 + (d - 1) / 7] += entry; } offs = (offs + dim) % 7; date.add(Calendar.MONTH, 1); } System.out.printf("%" + (w / 2 + 10) + "s%n", "[Snoopy Picture]"); System.out.printf("%" + (w / 2 + 4) + "s%n%n", year); for (int r = 0; r < nRows; r++) { for (int i = 0; i < 8; i++) { for (int c = r * nCols; c < (r + 1) * nCols && c < 12; c++) System.out.printf(" %s", mons[c][i]); System.out.println(); } System.out.println(); } } } Output: [Snoopy Picture] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 ## Mathematica Calendar is set of routines for handling calendars; It is built into Mathematica. We're only going to use it for a two functions, namely, DayOfWeek and DaysBetween. Needs["Calendar"]; Monthly calendar takes a year and a month and returns a simply formatted calendar for that month. It knows about leap years. monthlyCalendar[y_, m_] := Module[{ days = {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday}, months = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}, d1, shortDays, offset, daysInMonth}, d1 = DayOfWeek[{y, m, 1}]; daysInMonth[year_, month_] := DaysBetween[{year, month, 1}, {If[month == 12, year + 1, year], If[month == 12, 1, month + 1], 1}]; shortDays = (StringTake[ToString[#], 3] & /@ days); offset = d1 /. Thread[days -> Range[0, 6]]; Grid[ Prepend[ Prepend[ Partition[ PadRight[PadLeft[Range[daysInMonth[y, m]], daysInMonth[y, m] + offset, ""], 36, "" ], 7], shortDays], {months[[m]], SpanFromLeft}]]] yearlyCalendar prints out calendars for each of the 12 months in the year. yearlyCalendar[y_] := Grid[Partition[Table[monthlyCalendar[y, k], {k, 12}], 3], Spacings -> {4, 2}]; ## Perl #!/usr/bin/perl use strict; use warnings; use Time::Local; my @names = qw/ JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC/; myyear = shift ||'2007';

for my $month (0..11) { print "$names[$month]$year\n";
print calendar($year,$month), "\n\n";
}

sub calendar {
my ($year,$month) = @_;
my @mon_days = qw/31 28 31 30 31 30 31 31 30 31 30 31/;
++$mon_days[1] if$year % 4 == 0 && ($year % 400 == 0 ||$year % 1
+00 != 0);

my $cal = " Sun Mon Tue Wed Thu Fri Sat\n"; # Months are indexed beginning at 0 my$time = timegm(0,0,0,1,$month,$year);
my $wday = (gmtime$time)[6];

$cal .= " " x$wday;

my $mday = 1; while ($mday <= $mon_days[$month]) {
$cal .= sprintf "%4s",$mday++;
$cal .= "\n" if ($wday + $mday -1) % 7 == 0; } return$cal;
}
# Let's use this as a placeholder until a better solution arrives, OK?

## Perl 6

Works with: Rakudo version 2015.12
my $months-per-col = 3; my @week-day-names = <Mo Tu We Th Fr Sa Su>; my @month-names = <Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec>; my Int$year = +(@*ARGS.shift || 1969);

say fmt-year($year); exit; sub fmt-year ($year) {

my $str = (' ' x 30) ~$year ~ "\n";

my Array @month-strs;
@month-strs[$_] = fmt-month($year, $_).lines.Array for 1 .. 12; loop ( my$month = 1; $month <= 12;$month += $months-per-col ) { while @month-strs[$month] {
for ^$months-per-col { next unless @month-strs[$month+$_];$str ~= @month-strs[$month+$_].shift;
$str ~= " " x 3; }$str ~= "\n";
}
$str ~= "\n"; } return$str;
}
sub fmt-month ($year,$month) {
my $str = sprintf "%-20s\n", @month-names[$month-1];
$str ~= @week-day-names~"\n"; my$date = DateTime.new(year => $year, month =>$month);
my $week-day =$date.day-of-week;

$str ~= (" " xx$week-day-1).join(" ");

for $date.day ..$date.days-in-month -> $day {$date = DateTime.new(year => $year, month =>$month, day => $day);$str ~= " " if 1 < $week-day < 8; if$week-day == 8 {
$str ~= "\n";$week-day = 1;
}
$str ~= sprintf "%2d",$day;

$week-day++; }$str ~= " " if $week-day < 8;$str ~= (" " xx 8-$week-day).join(" ");$str ~= "\n";
return str; } ## Phix Gregorian calender only. include builtins\timedate.e function centre(string s, integer width) integer pad = width-length(s), left = floor(pad/2), right = pad-left return repeat(' ',left)&s&repeat(' ',right) end function function one_month(integer year, integer month) integer dow = day_of_week(year,month,1) sequence ldm = adjust_timedate(iff(month=12?{year+1,1,1,0,0,0,0,0} :{year,month+1,1,0,0,0,0,0}), timedelta(days:=-1)) sequence res = {centre(format_timedate(ldm,"Mmmm"),20),"Su Mo Tu We Th Fr Sa"} integer lastday = ldm[DT_DAY] string line = repeat(' ',20) integer p = dow*3-2 for d=1 to lastday do line[p..p+1] = sprintf("%2d",d) p += 3 if dow=7 or d=lastday then res = append(res,line) line = repeat(' ',20) dow = 1 p = 1 else dow += 1 end if end for return res end function procedure print_calendar(integer year, integer width) sequence months = repeat(0,12) integer wide = floor((width+2)/22) printf(1,centre("[Spot Reserved For Snoopy]",width)&"\n") printf(1,centre(sprintf("%d",year),width)&"\n") for month=1 to 12 do months[month] = one_month(year,month) end for for month=1 to 12 by wide do for k=1 to 9 do -- (more than enough) integer any = 0 string line = "", this for j=0 to wide-1 do if length(line) then line &= " " end if if k>length(months[month+j]) then line &= repeat(' ',20) else line &= months[month+j][k] any = 1 end if end for if any=0 then exit end if printf(1,centre(line,width)&"\n") end for end for end procedure print_calendar(1969,80) printf(1,join(repeat("1234567890",8),"")&"\n") print_calendar(1969,132) printf(1,join(repeat("1234567890",13),"")&"12\n") Output: [Spot Reserved For Snoopy] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 12345678901234567890123456789012345678901234567890123456789012345678901234567890 [Spot Reserved For Snoopy] 1969 January February March April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 27 28 29 30 25 26 27 28 29 30 31 29 30 30 31 July August September October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 1 2 3 4 1 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 31 30 123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012 ## PicoLisp This "calendar" is nicely formatted, and fits into 20 columns ;-) (de cal (Year) (prinl "====== " Year " ======") (for Dat (range (date Year 1 1) (date Year 12 31)) (let D (date Dat) (tab (3 3 4 8) (when (= 1 (caddr D)) (get *Mon (cadr D)) ) (caddr D) (day Dat *Day) (when (=0 (% (inc Dat) 7)) (pack "Week " (week Dat)) ) ) ) ) ) (cal 1969) Output: ====== 1969 ====== Jan 1 Wed 2 Thu 3 Fri 4 Sat 5 Sun 6 Mon Week 2 7 Tue .... 28 Sat 29 Sun 30 Mon Week 27 Jul 1 Tue 2 Wed 3 Thu 4 Fri .... 25 Thu 26 Fri 27 Sat 28 Sun 29 Mon Week 53 30 Tue 31 Wed ## Pike the Calendar in Pike does not handle the transitions from the Julian to the Gregorian calendar, but it handles those separately. the default calendar is ISO, other options are Gregorian, Julian, Bahai, Coptic, Islamic and Discordian. this script also highlights holidays by region. regions may be chosen by 2-letter country name, as well as some special 'regions': christianity, orthodox, bahai, islamic, among others. #!/bin/env pike int main(int argc, array(string) argv) { object cal = Calendar; object year; string region = "us"; array date = argv[1..]; if (sizeof(date) && objectp(Calendar[date[0]]) && Calendar[date[0]]->Day) { cal = Calendar[date[0]]; date = Array.shift(date)[1]; } if (sizeof(date) && (int)date[0]) { year = cal.Year((int)date[0]); date = Array.shift(date)[1]; } if (sizeof(date)) region = date[0]; if (!year) year = cal.Year(); print_year(year, region); } array make_month(object month, int field_width, void|string region) { array out =({}); mapping holidays = ([]); object today = Calendar.Day(); if (region) holidays = Calendar.Events.find_region(region)->scan_events(month); array weekday_names = sprintf("%*.*s", field_width, field_width, month->week()->days()->week_day_shortname()[*]); out += ({ ({ month->month_name(), month->month_no(), month->year_name() }) }); out += ({ weekday_names }); out += showday(month->weeks()->days()[*][*], month, today, holidays, field_width); out += ({ ({ " "*field_width })*sizeof(weekday_names) }); return out; } string print_month(object _month, void|int field_width, void|string region) { if (!field_width) field_width = 2; array month = make_month(_month, field_width, region); string out = ""; out += sprintf("%|*s\n", (field_width+1)*sizeof(month[1])-1, sprintf("%s", month[0][0])); out += sprintf((month[1..][*]*" ")*"\n"); return out; } string print_year(object year, void|string region) { array output = ({}); int day_width = 2; int columns = Stdio.stdout.tcgetattr()->columns; int month_width = sizeof(make_month(year->month(), day_width)[1]) * (day_width+1) - 1; if (columns < month_width) columns = month_width; // try to find an optimal good looking solution to spread the months // across the terminal width // for the common calendar of 12 months this is easy but we need to // account for caledars that have more than 12 months float max_width = (float)((columns+2)/(month_width+2)); float max_height = ceil(year->number_of_months()/max_width); float w = max_width; while(ceil(year->number_of_months()/(w-1)) == max_height) w--; foreach(print_month(year->months()[*], day_width, region)/w;; array row) { array rows = row[*]/"\n"; int l = max(@sizeof(rows[*])); foreach(rows; int i;) { // the last line of each month is an empty line. // repeat the line as many times as needed to make the months equally long rows[i]+=({ rows[i][-1] })*(l-sizeof(rows[i])); } rows = Array.transpose(rows); output += rows[*]*" "; } write("%*|s\n", sizeof(output[1]), year->format_nice()); write(output * "\n"); write("\n"); } string showday(object day, object month, object today, mapping holidays, int field_width) { string dayname; if (day->month() == month) { dayname = (string)day->month_day(); dayname = " "*(sizeof((string)month->number_of_days())-sizeof(dayname))+dayname; if (day == today) dayname = sprintf("%|*.*s", field_width, field_width, dayname); else dayname = sprintf("%|*.*s", field_width, field_width, dayname); if (holidays[day]) dayname = sprintf("%|s", dayname); } else dayname = " "*field_width; return dayname; } Output: (holidays lost in copy-paste) 1969 January February March Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 6 7 8 9 10 11 12 3 4 5 6 7 8 9 3 4 5 6 7 8 9 13 14 15 16 17 18 19 10 11 12 13 14 15 16 10 11 12 13 14 15 16 20 21 22 23 24 25 26 17 18 19 20 21 22 23 17 18 19 20 21 22 23 27 28 29 30 31 24 25 26 27 28 24 25 26 27 28 29 30 31 April May June Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 4 1 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 30 July August September Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 1 2 3 4 5 6 7 7 8 9 10 11 12 13 4 5 6 7 8 9 10 8 9 10 11 12 13 14 14 15 16 17 18 19 20 11 12 13 14 15 16 17 15 16 17 18 19 20 21 21 22 23 24 25 26 27 18 19 20 21 22 23 24 22 23 24 25 26 27 28 28 29 30 31 25 26 27 28 29 30 31 29 30 October November December Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 3 4 5 6 7 6 7 8 9 10 11 12 3 4 5 6 7 8 9 8 9 10 11 12 13 14 13 14 15 16 17 18 19 10 11 12 13 14 15 16 15 16 17 18 19 20 21 20 21 22 23 24 25 26 17 18 19 20 21 22 23 22 23 24 25 26 27 28 27 28 29 30 31 24 25 26 27 28 29 30 29 30 31 ## PL/I calendar: procedure (year) options (main); declare year character (4) varying; declare (a, b, c) (0:5,0:6) character (3); declare name_month(12) static character (9) varying initial ( 'JANUARY', 'FEBRUARY', 'MARCH', 'APRIL', 'MAY', 'JUNE', 'JULY', 'AUGUST', 'SEPTEMBER', 'OCTOBER', 'NOVEMBER', 'DECEMBER'); declare i fixed; declare (mm, mmp1, mmp2) pic '99'; put edit (center('CALENDAR FOR ' || YEAR, 67)) (a); put skip (2); do mm = 1 to 12 by 3; mmp1 = mm + 1; mmp2 = mm + 2; call prepare_month('01' || mm || YEAR, a); call prepare_month('01' || mmp1 || YEAR, b); call prepare_month('01' || mmp2 || YEAR, c); put skip edit (center(name_month(mm), 23), center(name_month(mmp1), 23), center(name_month(mmp2), 23) ) (a); put skip edit ((3)' M T W T F S S ') (a); do i = 0 to 5; put skip edit (a(i,*), b(i,*), c(i,*)) (7 a, x(2)); end; end; prepare_month: procedure (start, month); declare month(0:5,0:6) character (3); declare start character (8); declare i pic 'ZZ9'; declare offset fixed; declare (j, day) fixed binary (31); declare (this_month, next_month, k) fixed binary; day = days(start, 'DDMMYYYY'); offset = weekday(day) - 1; if offset = 0 then offset = 7; month = ''; do j = day by 1; this_month = substr(daystodate(j, 'DDMMYYYY'), 3, 2); next_month = substr(daystodate(j+1, 'DDMMYYYY'), 3, 2); if this_month^= next_month then leave; end; i = 1; do k = offset-1 to offset+j-day-1; month(k/7, mod(k,7)) = i; i = i + 1; end; end prepare_month; end calendar; Output: CALENDAR FOR 1969 JANUARY FEBRUARY MARCH M T W T F S S M T W T F S S M T W T F S S 1 2 3 4 5 1 2 1 2 6 7 8 9 10 11 12 3 4 5 6 7 8 9 3 4 5 6 7 8 9 13 14 15 16 17 18 19 10 11 12 13 14 15 16 10 11 12 13 14 15 16 20 21 22 23 24 25 26 17 18 19 20 21 22 23 17 18 19 20 21 22 23 27 28 29 30 31 24 25 26 27 28 24 25 26 27 28 29 30 31 APRIL MAY JUNE M T W T F S S M T W T F S S M T W T F S S 1 2 3 4 5 6 1 2 3 4 1 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 30 JULY AUGUST SEPTEMBER M T W T F S S M T W T F S S M T W T F S S 1 2 3 4 5 6 1 2 3 1 2 3 4 5 6 7 7 8 9 10 11 12 13 4 5 6 7 8 9 10 8 9 10 11 12 13 14 14 15 16 17 18 19 20 11 12 13 14 15 16 17 15 16 17 18 19 20 21 21 22 23 24 25 26 27 18 19 20 21 22 23 24 22 23 24 25 26 27 28 28 29 30 31 25 26 27 28 29 30 31 29 30 OCTOBER NOVEMBER DECEMBER M T W T F S S M T W T F S S M T W T F S S 1 2 3 4 5 1 2 1 2 3 4 5 6 7 6 7 8 9 10 11 12 3 4 5 6 7 8 9 8 9 10 11 12 13 14 13 14 15 16 17 18 19 10 11 12 13 14 15 16 15 16 17 18 19 20 21 20 21 22 23 24 25 26 17 18 19 20 21 22 23 22 23 24 25 26 27 28 27 28 29 30 31 24 25 26 27 28 29 30 29 30 31 Extract for 2013: CALENDAR FOR 2013 JANUARY FEBRUARY MARCH M T W T F S S M T W T F S S M T W T F S S 1 2 3 4 5 6 1 2 3 1 2 3 7 8 9 10 11 12 13 4 5 6 7 8 9 10 4 5 6 7 8 9 10 14 15 16 17 18 19 20 11 12 13 14 15 16 17 11 12 13 14 15 16 17 21 22 23 24 25 26 27 18 19 20 21 22 23 24 18 19 20 21 22 23 24 28 29 30 31 25 26 27 28 25 26 27 28 29 30 31 ## Python The Python calendar.pryear function prints calendars with the following formatting options: optional parameters w, l, and c are for date column width, lines per week, and number of spaces between month columns, respectively. Although rumoured to be getting an anti-gravity module, Python as yet does not include a snoopy module ;-) >>> import calendar >>> help(calendar.prcal) Help on method pryear in module calendar: pryear(self, theyear, w=0, l=0, c=6, m=3) method of calendar.TextCalendar instance Print a years calendar. >>> calendar.prcal(1969) 1969 January February March Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 6 7 8 9 10 11 12 3 4 5 6 7 8 9 3 4 5 6 7 8 9 13 14 15 16 17 18 19 10 11 12 13 14 15 16 10 11 12 13 14 15 16 20 21 22 23 24 25 26 17 18 19 20 21 22 23 17 18 19 20 21 22 23 27 28 29 30 31 24 25 26 27 28 24 25 26 27 28 29 30 31 April May June Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 4 1 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 30 July August September Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 1 2 3 4 5 6 7 7 8 9 10 11 12 13 4 5 6 7 8 9 10 8 9 10 11 12 13 14 14 15 16 17 18 19 20 11 12 13 14 15 16 17 15 16 17 18 19 20 21 21 22 23 24 25 26 27 18 19 20 21 22 23 24 22 23 24 25 26 27 28 28 29 30 31 25 26 27 28 29 30 31 29 30 October November December Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 1 2 1 2 3 4 5 6 7 6 7 8 9 10 11 12 3 4 5 6 7 8 9 8 9 10 11 12 13 14 13 14 15 16 17 18 19 10 11 12 13 14 15 16 15 16 17 18 19 20 21 20 21 22 23 24 25 26 17 18 19 20 21 22 23 22 23 24 25 26 27 28 27 28 29 30 31 24 25 26 27 28 29 30 29 30 31 >>> print('1234567890'*8) 12345678901234567890123456789012345678901234567890123456789012345678901234567890 >>> ## Racket #lang racket (require racket/date net/base64 file/gunzip) (define (calendar yr) (define (nsplit n l) (if (null? l) l (cons (take l n) (nsplit n (drop l n))))) (define months (for/list ([mn (in-naturals 1)] [mname '(January February March April May June July August September October November December)]) (define s (find-seconds 0 0 12 1 mn yr)) (define pfx (date-week-day (seconds->date s))) (define days (let ([? (if (= mn 12) (λ(x y) y) (λ(x y) x))]) (round (/ (- (find-seconds 0 0 12 1 (? (+ 1 mn) 1) (? yr (+ 1 yr))) s) 60 60 24)))) (list* (~a mname #:width 20 #:align 'center) "Su Mo Tu We Th Fr Sa" (map string-join (nsplit 7 (,@(make-list pfx " ") ,@(for/list ([d days]) (~a (+ d 1) #:width 2 #:align 'right)) ,@(make-list (- 42 pfx days) " "))))))) (let ([s #"nZA7CsAgDED3nCLgoAU/3Uvv4SCE3qKD5OyNWvoBhdIHSswjMYp4YR2z80Tk8StOgP sY0EyrMZOE6WsL3u4G5lyV+d8MyVOy8hZBt7RSMca9Ac/KUIs1L/BOysb50XMtMzEj ZqiuRxIVqI+4kSpy7GqpXNsz+bfpfWIGOAA="] [o (open-output-string)]) (inflate (open-input-bytes (base64-decode s)) o) (display (regexp-replace #rx"~a" (get-output-string o) (~a yr)))) (for-each displayln (dropf-right (for*/list ([3ms (nsplit 3 months)] [s (apply map list 3ms)]) (regexp-replace #rx" +" (string-join s " ") ""))
(λ(s) (equal? "" s)))))

(calendar 1969)
Output:
,-~~-.___.                                         ----
/ ()=(()   \                                        1969
(   (        0                                       ----
\._\, ,----'
##XXXxxxxxxx
/  ---'~;
/    /~|-
=(   ~~  |
/~~~~~~~~~~~~~~~~~~~~~\
/_______________________\
/_________________________\
/___________________________\
|____________________|
|____________________|
|____________________|
|                    |

January                February                March
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4                      1                      1
5  6  7  8  9 10 11    2  3  4  5  6  7  8    2  3  4  5  6  7  8
12 13 14 15 16 17 18    9 10 11 12 13 14 15    9 10 11 12 13 14 15
19 20 21 22 23 24 25   16 17 18 19 20 21 22   16 17 18 19 20 21 22
26 27 28 29 30 31      23 24 25 26 27 28      23 24 25 26 27 28 29
30 31
April                   May                    June
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5                1  2  3    1  2  3  4  5  6  7
6  7  8  9 10 11 12    4  5  6  7  8  9 10    8  9 10 11 12 13 14
13 14 15 16 17 18 19   11 12 13 14 15 16 17   15 16 17 18 19 20 21
20 21 22 23 24 25 26   18 19 20 21 22 23 24   22 23 24 25 26 27 28
27 28 29 30            25 26 27 28 29 30 31   29 30

July                  August               September
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5                   1  2       1  2  3  4  5  6
6  7  8  9 10 11 12    3  4  5  6  7  8  9    7  8  9 10 11 12 13
13 14 15 16 17 18 19   10 11 12 13 14 15 16   14 15 16 17 18 19 20
20 21 22 23 24 25 26   17 18 19 20 21 22 23   21 22 23 24 25 26 27
27 28 29 30 31         24 25 26 27 28 29 30   28 29 30
31
October                November               December
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4                      1       1  2  3  4  5  6
5  6  7  8  9 10 11    2  3  4  5  6  7  8    7  8  9 10 11 12 13
12 13 14 15 16 17 18    9 10 11 12 13 14 15   14 15 16 17 18 19 20
19 20 21 22 23 24 25   16 17 18 19 20 21 22   21 22 23 24 25 26 27
26 27 28 29 30 31      23 24 25 26 27 28 29   28 29 30 31
30

## REXX

Rather than build a program from scratch, I took my generalized REXX program that generated (as an
option) any calendar for any month, and by extension, any number of months (so that an entire
year could be displayed/written).   To make the program much smaller, a LOT of code was removed
(but it's still a sledgehammer doing the work of a small hammer).

Some of the code removed:

• almost all error checking and the issuing of error messages.
• the option of using "simple" characters as opposed to a true grid (of ASCII extended characters).
• the option of highlighting of today's date.
• the option of using colors.
• the specifying of what lang:uage to use (over 90 languages, default is English).
• the option of using indentation.
• the option of using different date formats (to specify the date).
• the option of using a time addition/subtraction for the date (* -4score-7years).
• the option of showing the phases of the moon.
• the option of showing the day-of-the-year (as on financial calendars and others).
• the option of specifying a calendar fill character (those empty cells in a monthly calender).
• the option of drawing Snoopy (three versions) and also many other animals/ASCII art.
• the specifing of alternate outputs (a file/printer/XEDIT/stack/GLOBALVs/etc).
• the option of displaying the year in blocked form (at the top of the calendar):
11          9999999       6666666       9999999
111         999999999     666666666     999999999
1111        99      99    66      66    99      99
11        99      99    66            99      99
11        99     999    66            99     999
11         999999999    66 666666      999999999
11          99999 99    6666666666      99999 99
11                99    666     66            99
11                99    66      66            99
11        99      99    66      66    99      99
111111       99999999      66666666      99999999
111111        999999        666666        999999

Most of the code is dealing with drawing a cell (grid) for each day-of-the-month, so the program
is a bit more complex than it has to be for this task.   Also, it was designed for any year, any
month(s), and any size screen/device to show (display) it.   Accommodations were made in the program
to allow the choice of what type of cells would be generated: small/smaller/smallest for height, and
narrow/narrower/narrowest for the width.   The size (width/depth) of the output device/terminal can be
specified.   The choice could've been performed programmatically, but I never believe that a program
could best choose over what the user wants, as it depends on esthetics and looks (fashion).

/*REXX program to show any year's (monthly) calendar (with/without grid)*/

@abc='abcdefghijklmnopqrstuvwxyz'; @abcU=@abc; upper @abcU
calfill=' '; mc=12; _='1 3 1234567890' "fb"x
parse var _ grid calspaces # chk . cv_ days.1 days.2 days.3 daysn sd sw
_=0; parse var _ cols 1 jd 1 lowerCase 1 maxKalPuts 1 narrow 1,
narrower 1 narrowest 1 short 1 shorter 1 shortest 1,
small 1 smaller 1 smallest 1 upperCase
parse arg mm '/' dd "/" yyyy _ '(' ops; uops=ops
if _\=='' | \is#(mm) | \is#(dd) | \is#(yyyy) then call erx 86

do while ops\==''; ops=strip(ops,'L'); parse var ops _1 2 1 _ . 1 _o ops
upper _
select
when abb('CALSPaces') then calspaces=nai()
when abb('DEPth') then sd=nai()
when abbn('GRIDs') then grid=no()
when abbn('LOWercase') then lowerCase=no()
when abb('CALMONths') then mc=nai()
when abbn('NARrow') then narrow=no()
when abbn('NARROWER') then narrower=no()
when abbn('NARROWESt') then narrowest=no()
when abbn('SHORt') then short=no()
when abbn('SHORTER') then shorter=no()
when abbn('SHORTESt') then shortest=no()
when abbn('SMALl') then small=no()
when abbn('SMALLER') then smaller=no()
when abbn('SMALLESt') then smallest=no()
when abbn('UPPercase') then upperCase=no()
when abb('WIDth') then sw=nai()
otherwise nop
end /*select*/
end /*do while opts\== ...*/

mc=int(mc,'monthscalender'); if mc>0 then cal=1
days='Sunday Monday Tuesday Wednesday Thursday Friday Saturday'
months='January February March April May June July August September October November December'
days=' 'days; months=' 'months
cyyyy=right(date(),4); hyy=left(cyyyy,2); lyy=right(cyyyy,2)
dy.=31; _=30; parse var _ dy.4 1 dy.6 1 dy.9 1 dy.11; dy.2=28+ly(yyyy)
yy=right(yyyy,2); sd=p(sd 43); sw=p(sw 80); cw=10; cindent=1; calwidth=76
if small then do; narrow=1  ; short=1  ; end
if smaller then do; narrower=1 ; shorter=1 ; end
if smallest then do; narrowest=1; shortest=1; end
if shortest then shorter=1
if shorter then short =1
if narrow then do; cw=9; cindent=3; calwidth=69; end
if narrower then do; cw=4; cindent=1; calwidth=34; end
if narrowest then do; cw=2; cindent=1; calwidth=20; end
cv_=calwidth+calspaces+2
calfill=left(copies(calfill,cw),cw)
do j=1 for 7; _=word(days,j)
do jw=1 for 3; _d=strip(substr(_,cw*jw-cw+1,cw))
if jw=1 then _d=centre(_d,cw+1)
else _d=left(_d,cw+1)
days.jw=days.jw||_d
end /*jw*/
__=daysn
if narrower then daysn=__||centre(left(_,3),5)
if narrowest then daysn=__||center(left(_,2),3)
end /*j*/
_yyyy=yyyy; calPuts=0; cv=1; _mm=mm+0; month=word(months,mm)
dy.2=28+ly(_yyyy); dim=dy._mm; _dd=01; dow=dow(_mm,_dd,_yyyy); $dd=dd+0 /*─────────────────────────────now: the business of the building the cal*/ call calGen do _j=2 to mc if cv_\=='' then do cv=cv+cv_ if cv+cv_>=sw then do; cv=1; call calPut call fcalPuts;call calPb end else calPuts=0 end else do;call calPb;call calPut;call fcalPuts;end _mm=_mm+1; if _mm==13 then do; _mm=1; _yyyy=_yyyy+1; end month=word(months,_mm); dy.2=28+ly(_yyyy); dim=dy._mm dow=dow(_mm,_dd,_yyyy);$dd=0; call calGen
end /*_j*/
call fcalPuts
return _

/*─────────────────────────────calGen subroutine────────────────────────*/
calGen: cellX=;cellJ=;cellM=;calCells=0;calline=0
call calPut
call calPutl copies('─',calwidth),"┌┐"; call calHd
call calPutl month ' ' _yyyy  ; call calHd
if narrowest | narrower then call calPutl daysn
else do jw=1 for 3
if space(days.jw)\=='' then call calPutl days.jw
end
calft=1; calfb=0
do jf=1 for dow-1; call cellDraw calFill,calFill; end
do jy=1 for dim; call cellDraw jy; end
calfb=1
do 7; call cellDraw calFill,calFill; end
if sd>32 & \shorter then call calPut
return

/*─────────────────────────────cellDraw subroutine──────────────────────*/
cellDraw: parse arg zz,cdDOY;zz=right(zz,2);calCells=calCells+1
if calCells>7 then do
calLine=calLine+1
cellX=substr(cellX,2)
cellJ=substr(cellJ,2)
cellM=substr(cellM,2)
cellB=translate(cellX,,")(─-"#)
if calLine==1 then call cx
call calCsm; call calPutl cellX; call calCsj; call cx
cellX=; cellJ=; cellM=; calCells=1
end
cdDOY=right(cdDOY,cw); cellM=cellM'│'center('',cw)
cellX=cellX'│'centre(zz,cw); cellJ=cellJ'│'center('',cw)
return

/*═════════════════════════════general 1-line subs══════════════════════*/
abb:arg abbu;parse arg abb;return abbrev(abbu,_,abbl(abb))
abbl:return verify(arg(1)'a',@abc,'M')-1
abbn:parse arg abbn;return abb(abbn)|abb('NO'abbn)
calCsj:if sd>49&\shorter then call calPutl cellB;if sd>24&\short then call calPutl cellJ; return
calCsm:if sd>24&\short then call calPutl cellM;if sd>49&\shorter then call calPutl cellB;return
calHd:if sd>24&\shorter then call calPutl;if sd>32&\shortest then call calPutl;return
calPb:if \grid&shortest then call put chk;return
calPut:calPuts=calPuts+1;maxKalPuts=max(maxKalPuts,calPuts);if symbol('CT.'calPuts)\=='VAR' then ct.calPuts=;ct.calPuts=overlay(arg(1),ct.calPuts,cv);return
calPutl:call calPut copies(' ',cindent)left(arg(2)"│",1)center(arg(1),calwidth)||right('│'arg(2),1);return
cx:cx_='├┤';cx=copies(copies('─',cw)'┼',7);if calft then do;cx=translate(cx,'┬',"┼");calft=0;end;if calfb then do;cx=translate(cx,'┴',"┼");cx_='└┘';calfb=0;end;call calPutl cx,cx_;return
dow:procedure;arg m,d,y;if m<3 then do;m=m+12;y=y-1;end;yl=left(y,2);yr=right(y,2);w=(d+(m+1)*26%10+yr+yr%4+yl%4+5*yl)//7;if w==0 then w=7;return w
er:parse arg _1,_2;call '$ERR' "14"p(_1) p(word(_1,2) !fid(1)) _2;if _1<0 then return _1;exit result err:call er '-'arg(1),arg(2);return '' erx:call er '-'arg(1),arg(2);exit '' fcalPuts: do j=1 for maxKalPuts;call put ct.j;end;ct.=;maxKalPuts=0;calPuts=0;return int:int=numx(arg(1),arg(2));if \isint(int) then call erx 92,arg(1) arg(2);return int/1 is#:return verify(arg(1),#)==0 isint:return datatype(arg(1),'W') lower:return translate(arg(1),@abc,@abcU) ly:arg _;if length(_)==2 then _=hyy||_;ly=_//4==0;if ly==0 then return 0;ly=((_//100\==0)|_//400==0);return ly na:if arg(1)\=='' then call erx 01,arg(2);parse var ops na ops;if na=='' then call erx 35,_o;return na nai:return int(na(),_o) nan:return numx(na(),_o) no:if arg(1)\=='' then call erx 01,arg(2);return left(_,2)\=='NO' num:procedure;parse arg x .,f,q;if x=='' then return x;if datatype(x,'N') then return x/1;x=space(translate(x,,','),0);if datatype(x,'N') then return x/1;return numnot() numnot:if q==1 then return x;if q=='' then call er 53,x f;call erx 53,x f numx:return num(arg(1),arg(2),1) p:return word(arg(1),1) put:_=arg(1);_=translate(_,,'_'chk);if \grid then _=ungrid(_);if lowerCase then _=lower(_);if upperCase then upper _;if shortest&_=' ' then return;call tell _;return tell:say arg(1);return ungrid:return translate(arg(1),,"│║─═┤┐└┴┬├┼┘┌╔╗╚╝╟╢╞╡╫╪╤╧╥╨╠╣") output when using the input of: 1/1/1969 (noGrid smallest narrowest) «Snoopy "picture" here» January 1969 February 1969 March 1969 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April 1969 May 1969 June 1969 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July 1969 August 1969 September 1969 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October 1969 November 1969 December 1969 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30 Output when using the input of: 1/1/1969 (smallest narrowest width 156 calSpaces 5) A width of 156 was used to illustrate showing a grid, otherwise it would fit in 132 columns. ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ │ January 1969 │ │ February 1969 │ │ March 1969 │ │ April 1969 │ │ May 1969 │ │ June 1969 │ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ │ │ │ │ 1│ 2│ 3│ 4│ │ │ │ │ │ │ │ 1│ │ │ │ │ │ │ │ 1│ │ │ │ 1│ 2│ 3│ 4│ 5│ │ │ │ │ │ 1│ 2│ 3│ │ 1│ 2│ 3│ 4│ 5│ 6│ 7│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │ 5│ 6│ 7│ 8│ 9│10│11│ │ 2│ 3│ 4│ 5│ 6│ 7│ 8│ │ 2│ 3│ 4│ 5│ 6│ 7│ 8│ │ 6│ 7│ 8│ 9│10│11│12│ │ 4│ 5│ 6│ 7│ 8│ 9│10│ │ 8│ 9│10│11│12│13│14│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │12│13│14│15│16│17│18│ │ 9│10│11│12│13│14│15│ │ 9│10│11│12│13│14│15│ │13│14│15│16│17│18│19│ │11│12│13│14│15│16│17│ │15│16│17│18│19│20│21│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │19│20│21│22│23│24│25│ │16│17│18│19│20│21│22│ │16│17│18│19│20│21│22│ │20│21│22│23│24│25│26│ │18│19│20│21│22│23│24│ │22│23│24│25│26│27│28│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │26│27│28│29│30│31│ │ │23│24│25│26│27│28│ │ │23│24│25│26│27│28│29│ │27│28│29│30│ │ │ │ │25│26│27│28│29│30│31│ │29│30│ │ │ │ │ │ └──┴──┴──┴──┴──┴──┴──┘ └──┴──┴──┴──┴──┴──┴──┘ ├──┼──┼──┼──┼──┼──┼──┤ └──┴──┴──┴──┴──┴──┴──┘ └──┴──┴──┴──┴──┴──┴──┘ └──┴──┴──┴──┴──┴──┴──┘ │30│31│ │ │ │ │ │ └──┴──┴──┴──┴──┴──┴──┘ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ ┌────────────────────┐ │ July 1969 │ │ August 1969 │ │ September 1969 │ │ October 1969 │ │ November 1969 │ │ December 1969 │ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ │Su Mo Tu We Th Fr Sa│ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ ├──┬──┬──┬──┬──┬──┬──┤ │ │ │ 1│ 2│ 3│ 4│ 5│ │ │ │ │ │ │ 1│ 2│ │ │ 1│ 2│ 3│ 4│ 5│ 6│ │ │ │ │ 1│ 2│ 3│ 4│ │ │ │ │ │ │ │ 1│ │ │ 1│ 2│ 3│ 4│ 5│ 6│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │ 6│ 7│ 8│ 9│10│11│12│ │ 3│ 4│ 5│ 6│ 7│ 8│ 9│ │ 7│ 8│ 9│10│11│12│13│ │ 5│ 6│ 7│ 8│ 9│10│11│ │ 2│ 3│ 4│ 5│ 6│ 7│ 8│ │ 7│ 8│ 9│10│11│12│13│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │13│14│15│16│17│18│19│ │10│11│12│13│14│15│16│ │14│15│16│17│18│19│20│ │12│13│14│15│16│17│18│ │ 9│10│11│12│13│14│15│ │14│15│16│17│18│19│20│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │20│21│22│23│24│25│26│ │17│18│19│20│21│22│23│ │21│22│23│24│25│26│27│ │19│20│21│22│23│24│25│ │16│17│18│19│20│21│22│ │21│22│23│24│25│26│27│ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ ├──┼──┼──┼──┼──┼──┼──┤ │27│28│29│30│31│ │ │ │24│25│26│27│28│29│30│ │28│29│30│ │ │ │ │ │26│27│28│29│30│31│ │ │23│24│25│26│27│28│29│ │28│29│30│31│ │ │ │ └──┴──┴──┴──┴──┴──┴──┘ ├──┼──┼──┼──┼──┼──┼──┤ └──┴──┴──┴──┴──┴──┴──┘ └──┴──┴──┴──┴──┴──┴──┘ ├──┼──┼──┼──┼──┼──┼──┤ └──┴──┴──┴──┴──┴──┴──┘ │31│ │ │ │ │ │ │ │30│ │ │ │ │ │ │ └──┴──┴──┴──┴──┴──┴──┘ └──┴──┴──┴──┴──┴──┴──┘ ,-~~-.___. / ()=(() \ ( ( 0 \._\, ,----' ##XXXxxxxxxx / ---'~; / /~|- =( ~~ | /~~~~~~~~~~~~~~~~~~~~~\ /_______________________\ /_________________________\ /___________________________\ |____________________| |____________________| |____________________| | | ## Ruby Date class, from the standard library, knows how many days in a month, and which day is Sunday, for both Julian and Gregorian calendars. This program uses Date class, plus its own assumptions, to create the calendar. This program assumes that every year has 12 months and starts with January 1, and every month fits in 6 weeks starting with Sunday. require 'date' # Creates a calendar of _year_. Returns this calendar as a multi-line # string fit to _columns_. def cal(year, columns) # Start at January 1. # # Date::ENGLAND marks the switch from Julian calendar to Gregorian # calendar at 1752 September 14. This removes September 3 to 13 from # year 1752. (By fortune, it keeps January 1.) # date = Date.new(year, 1, 1, Date::ENGLAND) # Collect calendars of all 12 months. months = (1..12).collect do |month| rows = [Date::MONTHNAMES[month].center(20), "Su Mo Tu We Th Fr Sa"] # Make array of 42 days, starting with Sunday. days = [] date.wday.times { days.push " " } while date.month == month days.push("%2d" % date.mday) date += 1 end (42 - days.length).times { days.push " " } days.each_slice(7) { |week| rows.push(week.join " ") } next rows end # Calculate months per row (mpr). # 1. Divide columns by 22 columns per month, rounded down. (Pretend # to have 2 extra columns; last month uses only 20 columns.) # 2. Decrease mpr if 12 months would fit in the same months per # column (mpc). For example, if we can fit 5 mpr and 3 mpc, then # we use 4 mpr and 3 mpc. mpr = (columns + 2).div 22 mpr = 12.div((12 + mpr - 1).div mpr) # Use 20 columns per month + 2 spaces between months. width = mpr * 22 - 2 # Join months into calendar. rows = ["[Snoopy]".center(width), "#{year}".center(width)] months.each_slice(mpr) do |slice| slice[0].each_index do |i| rows.push(slice.map {|a| a[i]}.join " ") end end return rows.join("\n") end ARGV.length == 1 or abort "usage: #{$0} year"

# Guess width of terminal.
# 1. Obey environment variable COLUMNS.
# 2. Try to require 'io/console' from Ruby 1.9.3.
# 3. Try to run tput co.
# 4. Assume 80 columns.
columns = begin Integer(ENV["COLUMNS"] || "")
rescue
begin require 'io/console'; IO.console.winsize[1]
rescue LoadError
begin Integer(tput cols`)
rescue
80; end; end; end

puts cal(Integer(ARGV[0]), columns)

Here is 1969 in 132 columns.

$ruby cal.rb 1969 [Snoopy] 1969 January February March April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 27 28 29 30 25 26 27 28 29 30 31 29 30 30 31 July August September October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 1 2 3 4 1 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 31 30 The output in 80 columns is similar, except that there are only three months per row, and the "[Snoopy]" and "1969" are centered above February. ## Scala Library: Scala ### Scala Version 1 import java.util.{ Calendar, GregorianCalendar } import language.postfixOps import collection.mutable.ListBuffer object CalendarPrint extends App { val locd = java.util.Locale.getDefault() val cal = new GregorianCalendar val monthsMax = cal.getMaximum(Calendar.MONTH) def JDKweekDaysToISO(dn: Int) = { val nday = dn - Calendar.MONDAY if (nday < 0) (dn + Calendar.THURSDAY) else nday } def daysInMonth(year: Int, monthMinusOne: Int): Int = { cal.set(year, monthMinusOne, 1) cal.getActualMaximum(Calendar.DAY_OF_MONTH) } def namesOfMonths() = { def f1(i: Int): String = { cal.set(2013, i, 1) cal.getDisplayName(Calendar.MONTH, Calendar.LONG, locd) } (0 to monthsMax) map f1 } def offsets(year: Int): List[Int] = { val months = cal.getMaximum(Calendar.MONTH) def get1stDayOfWeek(i: Int) = { cal.set(year, i, 1) cal.get(Calendar.DAY_OF_WEEK) } (0 to monthsMax).toList map get1stDayOfWeek map { i => JDKweekDaysToISO(i) } } def headerNameOfDays() = { val mdow = cal.getDisplayNames(Calendar.DAY_OF_WEEK, Calendar.SHORT, locd) // map days of week val it = mdow.keySet.iterator val keySet = new ListBuffer[String] while (it.hasNext) keySet += it.next (keySet.map { key => (JDKweekDaysToISO(mdow.get(key)), key.take(2)) }.sortWith(_._1 < _._1) map (_._2)).mkString(" ") } def getGregCal(year: Int) = { { def dayOfMonth(month: Int) = new Iterator[(Int, Int)] { cal.set(year, month, 1) var ldom = 0 def next() = { val res = (cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH)) ldom = res._2 cal.roll(Calendar.DAY_OF_MONTH, true) res } def hasNext() = (cal.get(Calendar.DAY_OF_MONTH) > ldom) } var ret: List[(Int, Int)] = Nil for (i <- 0 to monthsMax) ret = ret ++ (dayOfMonth(i).toSeq) (ret, offsets(year)) } } def printCalendar(calendar: (List[(Int, Int)], List[Int]), headerList: List[String] = Nil, printerWidth: Int = 80) = { val mw = 20 // month width val gwf = 2 // gap width fixed val gwm = 2 // gap width minimum val fgw = true val arr = Array.ofDim[String](6, 7) def limits(printerWidth: Int): (Int, Int, Int, Int, Int) = { val pw = if (printerWidth < 20) 20 else if (printerWidth > 300) 300 else printerWidth // months side by side, gaps sum minimum val (msbs, gsm) = { val x1 = { val c = if (pw / mw > 12) 12 else pw / mw val a = (c - 1) if (c * mw + a * gwm <= pw) c else a } match { case 5 => 4 case a if (a > 6 && a < 12) => 6 case other => other } (x1, (x1 - 1) * gwm) } def getFGW(msbs: Int, gsm: Int) = { val r = (pw - msbs * mw - gsm) / 2; (r, gwf, r) } // fixed gap width def getVGW(msbs: Int, gsm: Int) = pw - msbs * mw - gsm match { // variable gap width case a if (a < 2 * gwm) => (a / 2, gwm, a / 2) case b => { val x = (b + gsm) / (msbs + 1); (x, x, x) } } // left margin, gap width, right margin val (lm, gw, rm) = if (fgw) getFGW(msbs, gsm) else getVGW(msbs, gsm) (pw, msbs, lm, gw, rm) } // def limits( val (pw, msbs, lm, gw, rm) = limits(printerWidth) val monthsList = (0 to monthsMax).map { m => calendar._1.filter { _._1 == m } } val nom = namesOfMonths() val hnod = headerNameOfDays def fsplit(list: List[(Int, Int)]): List[String] = { def fap(p: Int) = (p / 7, p % 7) for (i <- 0 until 6) for (j <- 0 until 7) arr(i)(j) = " " for (i <- 0 until list.size) arr(fap(i + calendar._2(list(i)._1))._1)(fap(i + calendar._2(list(i)._1))._2) = f"${(list(i)._2)}%2d"
arr.toList.map(_.foldRight("")(_ + " " + _))
}
val monthsRows = monthsList.map(fsplit)

def center(s: String, l: Int): String = {
(if (s.size >= l) s
else " " * ((l - s.size) / 2) + s + " " * ((l - s.size) / 2) + " ").substring(0, l)
}

val maxMonths = monthsMax + 1

val rowblocks = (1 to maxMonths / msbs).map { i =>
(0 to 5).map { j =>
val lb = new ListBuffer[String]
val k = (i - 1) * msbs
(k to k + msbs - 1).map { l => lb += monthsRows(l)(j) }
lb
}
}

val mheaders = (1 to maxMonths / msbs).
map { i => (0 to msbs - 1).map { j => center(nom(j + (i - 1) * msbs), 20) } }
val dowheaders = (1 to maxMonths / msbs).
map { i => (0 to msbs - 1).map { j => center(hnod, 20) } }

headerList.foreach(xs => println(center(xs + '\n', pw)))
(1 to 12 / msbs).foreach { i =>
println(" " * lm + mheaders(i - 1).foldRight("")(_ + " " * gw + _))
println(" " * lm + dowheaders(i - 1).foldRight("")(_ + " " * gw + _))
rowblocks(i - 1).foreach { xs => println(" " * lm + xs.foldRight("")(_ + " " * (gw - 1) + _)) }
println
}
} // def printCal(

printCalendar(getGregCal(1969), List("[Snoopy Picture]", "1969"))
printCalendar(getGregCal(1582), List("[Snoopy Picture]", "1582"), printerWidth = 132)
}
Output:
[Snoopy Picture]

1969

January               February               March
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1  2  3  4  5                  1  2                  1  2
6  7  8  9 10 11 12   3  4  5  6  7  8  9   3  4  5  6  7  8  9
13 14 15 16 17 18 19  10 11 12 13 14 15 16  10 11 12 13 14 15 16
20 21 22 23 24 25 26  17 18 19 20 21 22 23  17 18 19 20 21 22 23
27 28 29 30 31        24 25 26 27 28        24 25 26 27 28 29 30
31

April                  May                   June
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1  2  3  4  5  6            1  2  3  4                     1
7  8  9 10 11 12 13   5  6  7  8  9 10 11   2  3  4  5  6  7  8
14 15 16 17 18 19 20  12 13 14 15 16 17 18   9 10 11 12 13 14 15
21 22 23 24 25 26 27  19 20 21 22 23 24 25  16 17 18 19 20 21 22
28 29 30              26 27 28 29 30 31     23 24 25 26 27 28 29
30

July                 August              September
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1  2  3  4  5  6               1  2  3   1  2  3  4  5  6  7
7  8  9 10 11 12 13   4  5  6  7  8  9 10   8  9 10 11 12 13 14
14 15 16 17 18 19 20  11 12 13 14 15 16 17  15 16 17 18 19 20 21
21 22 23 24 25 26 27  18 19 20 21 22 23 24  22 23 24 25 26 27 28
28 29 30 31           25 26 27 28 29 30 31  29 30

October               November              December
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1  2  3  4  5                  1  2   1  2  3  4  5  6  7
6  7  8  9 10 11 12   3  4  5  6  7  8  9   8  9 10 11 12 13 14
13 14 15 16 17 18 19  10 11 12 13 14 15 16  15 16 17 18 19 20 21
20 21 22 23 24 25 26  17 18 19 20 21 22 23  22 23 24 25 26 27 28
27 28 29 30 31        24 25 26 27 28 29 30  29 30 31

[Snoopy Picture]

1582

January               February               March                 April                  May                   June
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1  2  3  4  5  6  7            1  2  3  4            1  2  3  4                     1      1  2  3  4  5  6               1  2  3
8  9 10 11 12 13 14   5  6  7  8  9 10 11   5  6  7  8  9 10 11   2  3  4  5  6  7  8   7  8  9 10 11 12 13   4  5  6  7  8  9 10
15 16 17 18 19 20 21  12 13 14 15 16 17 18  12 13 14 15 16 17 18   9 10 11 12 13 14 15  14 15 16 17 18 19 20  11 12 13 14 15 16 17
22 23 24 25 26 27 28  19 20 21 22 23 24 25  19 20 21 22 23 24 25  16 17 18 19 20 21 22  21 22 23 24 25 26 27  18 19 20 21 22 23 24
29 30 31              26 27 28              26 27 28 29 30 31     23 24 25 26 27 28 29  28 29 30 31           25 26 27 28 29 30
30

July                 August              September              October               November              December
Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su  Mo Tu We Th Fr Sa Su
1         1  2  3  4  5                  1  2   1  2  3  4 15 16 17   1  2  3  4  5  6  7         1  2  3  4  5
2  3  4  5  6  7  8   6  7  8  9 10 11 12   3  4  5  6  7  8  9  18 19 20 21 22 23 24   8  9 10 11 12 13 14   6  7  8  9 10 11 12
9 10 11 12 13 14 15  13 14 15 16 17 18 19  10 11 12 13 14 15 16  25 26 27 28 29 30 31  15 16 17 18 19 20 21  13 14 15 16 17 18 19
16 17 18 19 20 21 22  20 21 22 23 24 25 26  17 18 19 20 21 22 23                        22 23 24 25 26 27 28  20 21 22 23 24 25 26
23 24 25 26 27 28 29  27 28 29 30 31        24 25 26 27 28 29 30                        29 30                 27 28 29 30 31
30 31

### Scala Version 2

Works with: Scala version 2.10.1
/**
* Loosely based on the Ruby implementation.
*
* Focuses on immutability and Scala idioms,
* while trying to remain readable and clean.
*/

object YearCalendarApp extends App with Extras {

val defaultYear = 1752
val columns = 86

val year = args.headOption.map(_.toInt).getOrElse(defaultYear)

yearCalendarLines(year, columns).foreach(println)

def yearCalendarLines(year: Int, columns: Int): Seq[String] = {
// At least one. Divide rest columns by width + 2 spaces (separator)
val calendarsPerRow = 1 + (columns - 20) / (20 + 2)

// Use 20 columns per month + 2 spaces between months
val width = calendarsPerRow * 22 - 2

List(
"[Snoopy]".center(width),
s"${year}".center(width)) ++ // Get, group, transpose and join calendar lines allMonthCalendarLines(year).grouped(calendarsPerRow).flatMap { calGroup => calGroup.transpose.map(stringsInRow => stringsInRow.mkString(" ")) } } def allMonthCalendarLines(year: Int): Seq[Seq[String]] = { (1 to 12).map { monthNr => val date = MonthCalendar(monthInYear = monthNr, year) // Make array of 42 days (7 * 6 weeks max.) starting with Sunday (which is 0) val daySlotsInMonth = { (Seq().padTo(date.dayOfWeek, " ") ++ date.daysInMonth.map { dayNr => "%2d".format(dayNr) }). padTo(42, " ") } List( date.monthName.center(20), "Su Mo Tu We Th Fr Sa") ++ daySlotsInMonth.grouped(7).map { weekSlots => weekSlots.mkString(" ") } } } } /** * This provides extra classes needed for the main * algorithm. */ trait Extras { import java.util.Calendar import java.util.GregorianCalendar import java.text.SimpleDateFormat import java.util.Locale import scala.collection.mutable.Buffer implicit class MyString(str: String) { def center(width: Int): String = { val leftSpaces = (width / 2) - (str.length() / 2) val rightSpaces = width - (leftSpaces + str.length) (" " * leftSpaces) + str + (" " * rightSpaces) } } case class MonthCalendar(monthInYear: Int, year: Int) { private val javaCalendar = makeJavaCalendar(year, monthInYear) private def makeJavaCalendar(year: Int, monthInYear: Int): Calendar = { val calendar = new GregorianCalendar() // Actually, other countries changed already in 1582, // which is the JDK's default implementation. val gregorianDateChangeInEngland = { val d = Calendar.getInstance() d.set(1752, Calendar.SEPTEMBER, 14) d.getTime() } // For England we need to set this explicitly. calendar.setGregorianChange(gregorianDateChangeInEngland) calendar.set(Calendar.DAY_OF_MONTH, 1) calendar.set(Calendar.YEAR, year) calendar.set(Calendar.MONTH, monthInYear - 1) calendar } val monthName = javaCalendar.getDisplayName(Calendar.MONTH, Calendar.LONG, Locale.ENGLISH) val dayOfWeek = javaCalendar.get(Calendar.DAY_OF_WEEK) - 1 val daysInMonth = { val tempCal = makeJavaCalendar(year, monthInYear) val dayNumbers = Buffer[Int]() while (tempCal.get(Calendar.MONTH) == monthInYear - 1) { dayNumbers += tempCal.get(Calendar.DAY_OF_MONTH) tempCal.add(Calendar.DATE, 1) } dayNumbers } } } Sample output for 1792: [Snoopy] 1752 January February March April Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9 10 11 2 3 4 5 6 7 8 8 9 10 11 12 13 14 5 6 7 8 9 10 11 12 13 14 15 16 17 18 9 10 11 12 13 14 15 15 16 17 18 19 20 21 12 13 14 15 16 17 18 19 20 21 22 23 24 25 16 17 18 19 20 21 22 22 23 24 25 26 27 28 19 20 21 22 23 24 25 26 27 28 29 30 31 23 24 25 26 27 28 29 29 30 31 26 27 28 29 30 May June July August Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 1 2 3 4 5 6 1 2 3 4 1 3 4 5 6 7 8 9 7 8 9 10 11 12 13 5 6 7 8 9 10 11 2 3 4 5 6 7 8 10 11 12 13 14 15 16 14 15 16 17 18 19 20 12 13 14 15 16 17 18 9 10 11 12 13 14 15 17 18 19 20 21 22 23 21 22 23 24 25 26 27 19 20 21 22 23 24 25 16 17 18 19 20 21 22 24 25 26 27 28 29 30 28 29 30 26 27 28 29 30 31 23 24 25 26 27 28 29 31 30 31 September October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 14 15 16 1 2 3 4 5 6 7 1 2 3 4 1 2 17 18 19 20 21 22 23 8 9 10 11 12 13 14 5 6 7 8 9 10 11 3 4 5 6 7 8 9 24 25 26 27 28 29 30 15 16 17 18 19 20 21 12 13 14 15 16 17 18 10 11 12 13 14 15 16 22 23 24 25 26 27 28 19 20 21 22 23 24 25 17 18 19 20 21 22 23 29 30 31 26 27 28 29 30 24 25 26 27 28 29 30 31 ## Seed7$ include "seed7_05.s7i";
include "time.s7i";

const func string: center (in string: stri, in integer: length) is
return ("" lpad (length - length(stri)) div 2 <& stri) rpad length;

const proc: printCalendar (in integer: year, in integer: cols) is func
local
var time: date is time.value;
var integer: dayOfWeek is 0;
const array string: monthNames is [] ("January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December");
var array array string: monthTable is 12 times 9 times "";
var string: str is "";
var integer: month is 0;
var integer: position is 0;
var integer: row is 0;
var integer: column is 0;
var integer: line is 0;
begin
for month range 1 to 12 do
monthTable[month][1] := " " & center(monthNames[month], 20);
monthTable[month][2] := " Mo Tu We Th Fr Sa Su";
date := date(year, month, 1);
dayOfWeek := dayOfWeek(date);
for position range 1 to 43 do
if position >= dayOfWeek and position - dayOfWeek < daysInMonth(date.year, date.month) then
str := succ(position - dayOfWeek) lpad 3;
else
str := "" lpad 3;
end if;
monthTable[month][3 + pred(position) div 7] &:= str;
end for;
end for;
writeln(center("[Snoopy Picture]", cols * 24 + 4));
writeln(center(str(year),cols * 24 + 4));
writeln;
for row range 1 to succ(11 div cols) do
for line range 1 to 9 do
for column range 1 to cols do
if pred(row) * cols + column <= 12 then
write(" " & monthTable[pred(row) * cols + column][line]);
end if;
end for;
writeln;
end for;
end for;
end func;

const proc: main is func
begin
printCalendar(1969, 3);
end func;

Original source: [1]

The output of this program is:

[Snoopy Picture]
1969

January                 February                 March
Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su
1  2  3  4  5                    1  2                    1  2
6  7  8  9 10 11 12     3  4  5  6  7  8  9     3  4  5  6  7  8  9
13 14 15 16 17 18 19    10 11 12 13 14 15 16    10 11 12 13 14 15 16
20 21 22 23 24 25 26    17 18 19 20 21 22 23    17 18 19 20 21 22 23
27 28 29 30 31          24 25 26 27 28          24 25 26 27 28 29 30
31

April                    May                     June
Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su
1  2  3  4  5  6              1  2  3  4                       1
7  8  9 10 11 12 13     5  6  7  8  9 10 11     2  3  4  5  6  7  8
14 15 16 17 18 19 20    12 13 14 15 16 17 18     9 10 11 12 13 14 15
21 22 23 24 25 26 27    19 20 21 22 23 24 25    16 17 18 19 20 21 22
28 29 30                26 27 28 29 30 31       23 24 25 26 27 28 29
30

July                   August                September
Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su
1  2  3  4  5  6                 1  2  3     1  2  3  4  5  6  7
7  8  9 10 11 12 13     4  5  6  7  8  9 10     8  9 10 11 12 13 14
14 15 16 17 18 19 20    11 12 13 14 15 16 17    15 16 17 18 19 20 21
21 22 23 24 25 26 27    18 19 20 21 22 23 24    22 23 24 25 26 27 28
28 29 30 31             25 26 27 28 29 30 31    29 30

October                 November                December
Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su    Mo Tu We Th Fr Sa Su
1  2  3  4  5                    1  2     1  2  3  4  5  6  7
6  7  8  9 10 11 12     3  4  5  6  7  8  9     8  9 10 11 12 13 14
13 14 15 16 17 18 19    10 11 12 13 14 15 16    15 16 17 18 19 20 21
20 21 22 23 24 25 26    17 18 19 20 21 22 23    22 23 24 25 26 27 28
27 28 29 30 31          24 25 26 27 28 29 30    29 30 31

## Sidef

Translation of: Perl 6
require('DateTime');

define months_per_col = 3
define week_day_names = <Mo Tu We Th Fr Sa Su>
define month_names = <Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec>

func fmt_month (year, month) {
var str = sprintf("%-20s\n", month_names[month-1])
str += week_day_names.join(' ')+"\n"

var dt = %s'DateTime'
var date = dt.new(year => year, month => month)
var week_day = date.day_of_week
str += ([" "] * week_day-1 -> join(" "))

var last_day = dt.last_day_of_month(year => year, month => month).day
date.day ... last_day -> each { |day|
date = dt.new(year => year, month => month, day => day)

str += " " if (week_day ~~ 2...7)
if (week_day == 8) {
str += "\n"
week_day = 1
}
str += sprintf("%2d", day)
++week_day
}
str += " " if (week_day < 8)
str += ([" "] * 8-week_day -> join(" "))
str += "\n"
}

func fmt_year (year) {
var month_strs = 12.of { |i| fmt_month(year, i).lines }

var str = (' '*30 + year + "\n")
for (var month = 0; month < 12; month += months_per_col) {
while (month_strs[month]) {
months_per_col.times { |i|
month_strs[month + i - 1] || next;
str += month_strs[month + i - 1].shift;
str += ' '*3
}
str += "\n"
}
str += "\n"
}

return str
}

print fmt_year(ARGV.is_empty ? 1969 : ARGV[0].to_i)
Output:
1969
Jan                    Feb                    Mar
Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su
1  2  3  4  5                   1  2                   1  2
6  7  8  9 10 11 12    3  4  5  6  7  8  9    3  4  5  6  7  8  9
13 14 15 16 17 18 19   10 11 12 13 14 15 16   10 11 12 13 14 15 16
20 21 22 23 24 25 26   17 18 19 20 21 22 23   17 18 19 20 21 22 23
27 28 29 30 31         24 25 26 27 28         24 25 26 27 28 29 30

Apr                    May                    Jun
Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su
1  2  3  4  5  6             1  2  3  4                      1
7  8  9 10 11 12 13    5  6  7  8  9 10 11    2  3  4  5  6  7  8
14 15 16 17 18 19 20   12 13 14 15 16 17 18    9 10 11 12 13 14 15
21 22 23 24 25 26 27   19 20 21 22 23 24 25   16 17 18 19 20 21 22
28 29 30               26 27 28 29 30 31      23 24 25 26 27 28 29

Jul                    Aug                    Sep
Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su
1  2  3  4  5  6                1  2  3    1  2  3  4  5  6  7
7  8  9 10 11 12 13    4  5  6  7  8  9 10    8  9 10 11 12 13 14
14 15 16 17 18 19 20   11 12 13 14 15 16 17   15 16 17 18 19 20 21
21 22 23 24 25 26 27   18 19 20 21 22 23 24   22 23 24 25 26 27 28
28 29 30 31            25 26 27 28 29 30 31   29 30

Oct                    Nov                    Dec
Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su   Mo Tu We Th Fr Sa Su
1  2  3  4  5                   1  2    1  2  3  4  5  6  7
6  7  8  9 10 11 12    3  4  5  6  7  8  9    8  9 10 11 12 13 14
13 14 15 16 17 18 19   10 11 12 13 14 15 16   15 16 17 18 19 20 21
20 21 22 23 24 25 26   17 18 19 20 21 22 23   22 23 24 25 26 27 28
27 28 29 30 31         24 25 26 27 28 29 30   29 30 31

## Tcl

Due to the prevalence of 80 column devices instead of 132 column ones, this code produces 3 months at a time instead of 4.

package require Tcl 8.5

# Produce information about the days in a month, without any assumptions about
# what those days actually are.
proc calMonthDays {timezone locale year month} {
set days {}
set moment [clock scan [format "%04d-%02d-00 12:00" $year$month] \
-timezone $timezone -locale$locale -format "%Y-%m-%d %H:%M"]
while 1 {
set moment [clock add $moment 1 day] lassign [clock format$moment -timezone $timezone -locale$locale \
-format "%m %d %u"] m d dow
if {[scan $m %d] !=$month} {
return $days } lappend days$moment [scan $d %d]$dow
}
}

proc calMonth {year month timezone locale} {
set dow 0
set line ""
set lines {}
foreach {t day dayofweek} [calMonthDays $timezone$locale $year$month] {
if {![llength $lines]} {lappend lines$t}
if {$dow >$dayofweek} {
lappend lines [string trimright $line] set line "" set dow 0 } while {$dow < $dayofweek-1} { append line " " incr dow } append line [format "%2d "$day]
set dow $dayofweek } lappend lines [string trimright$line]
}

proc cal3Month {year month timezone locale} {
# Extract the month data
set d1 [lassign [calMonth $year$month $timezone$locale] t1]; incr month
set d2 [lassign [calMonth $year$month $timezone$locale] t2]; incr month
set d3 [lassign [calMonth $year$month $timezone$locale] t3]
# Print the header line of month names
foreach t [list $t1$t2 $t3] { set m [clock format$t -timezone $timezone -locale$locale -format "%B"]
set l [expr {10 + [string length $m]/2}] puts -nonewline [format "%-25s" [format "%*s"$l $m]] } puts "" # Print the month days foreach l1$d1 l2 $d2 l3$d3 {
puts [format "%-25s%-25s%s" $l1$l2 $l3] } } proc cal {{year ""} {timezone :localtime} {locale en}} { if {$year eq ""} {
set year [clock format [clock seconds] -format %Y]
}
puts [format "%40s" "-- $year --"] foreach m {1 4 7 10} { puts "" cal3Month$year $m$timezone \$locale
}
}

proc snoopy {} {
puts [format "%43s\n" {[Snoopy Picture]}]
}

snoopy
cal

Which produces this output:

[Snoopy Picture]

-- 2011 --

January                  February                  March
1  2         1  2  3  4  5  6         1  2  3  4  5  6
3  4  5  6  7  8  9      7  8  9 10 11 12 13      7  8  9 10 11 12 13
10 11 12 13 14 15 16     14 15 16 17 18 19 20     14 15 16 17 18 19 20
17 18 19 20 21 22 23     21 22 23 24 25 26 27     21 22 23 24 25 26 27
24 25 26 27 28 29 30     28                       28 29 30 31
31

April                     May                      June
1  2  3                        1            1  2  3  4  5
4  5  6  7  8  9 10      2  3  4  5  6  7  8      6  7  8  9 10 11 12
11 12 13 14 15 16 17      9 10 11 12 13 14 15     13 14 15 16 17 18 19
18 19 20 21 22 23 24     16 17 18 19 20 21 22     20 21 22 23 24 25 26
25 26 27 28 29 30        23 24 25 26 27 28 29     27 28 29 30
30 31

July                    August                 September
1  2  3      1  2  3  4  5  6  7               1  2  3  4
4  5  6  7  8  9 10      8  9 10 11 12 13 14      5  6  7  8  9 10 11
11 12 13 14 15 16 17     15 16 17 18 19 20 21     12 13 14 15 16 17 18
18 19 20 21 22 23 24     22 23 24 25 26 27 28     19 20 21 22 23 24 25
25 26 27 28 29 30 31     29 30 31                 26 27 28 29 30

October                  November                 December
1  2         1  2  3  4  5  6               1  2  3  4
3  4  5  6  7  8  9      7  8  9 10 11 12 13      5  6  7  8  9 10 11
10 11 12 13 14 15 16     14 15 16 17 18 19 20     12 13 14 15 16 17 18
17 18 19 20 21 22 23     21 22 23 24 25 26 27     19 20 21 22 23 24 25
24 25 26 27 28 29 30     28 29 30                 26 27 28 29 30 31
31

If a different year is chosen, it's printed…

snoopy
cal 1969
[Snoopy Picture]

-- 1969 --

January                  February                  March
1  2  3  4  5                     1  2                     1  2
6  7  8  9 10 11 12      3  4  5  6  7  8  9      3  4  5  6  7  8  9
13 14 15 16 17 18 19     10 11 12 13 14 15 16     10 11 12 13 14 15 16
20 21 22 23 24 25 26     17 18 19 20 21 22 23     17 18 19 20 21 22 23
27 28 29 30 31           24 25 26 27 28           24 25 26 27 28 29 30
31

April                     May                      June
1  2  3  4  5  6               1  2  3  4                        1
7  8  9 10 11 12 13      5  6  7  8  9 10 11      2  3  4  5  6  7  8
14 15 16 17 18 19 20     12 13 14 15 16 17 18      9 10 11 12 13 14 15
21 22 23 24 25 26 27     19 20 21 22 23 24 25     16 17 18 19 20 21 22
28 29 30                 26 27 28 29 30 31        23 24 25 26 27 28 29
30

July                    August                 September
1  2  3  4  5  6                  1  2  3      1  2  3  4  5  6  7
7  8  9 10 11 12 13      4  5  6  7  8  9 10      8  9 10 11 12 13 14
14 15 16 17 18 19 20     11 12 13 14 15 16 17     15 16 17 18 19 20 21
21 22 23 24 25 26 27     18 19 20 21 22 23 24     22 23 24 25 26 27 28
28 29 30 31              25 26 27 28 29 30 31     29 30

October                  November                 December
1  2  3  4  5                     1  2      1  2  3  4  5  6  7
6  7  8  9 10 11 12      3  4  5  6  7  8  9      8  9 10 11 12 13 14
13 14 15 16 17 18 19     10 11 12 13 14 15 16     15 16 17 18 19 20 21
20 21 22 23 24 25 26     17 18 19 20 21 22 23     22 23 24 25 26 27 28
27 28 29 30 31           24 25 26 27 28 29 30     29 30 31

The code also handles Julian/Gregorian switch dates correctly, but must be told what locale to format the switch as and for what timezone in that case. For example, Spain was one of the first countries to make the change:

snoopy
cal 1582 :Europe/Madrid es_ES
[Snoopy Picture]

-- 1582 --

enero                   febrero                   marzo
1  2  3  4  5  6  7               1  2  3  4               1  2  3  4
8  9 10 11 12 13 14      5  6  7  8  9 10 11      5  6  7  8  9 10 11
15 16 17 18 19 20 21     12 13 14 15 16 17 18     12 13 14 15 16 17 18
22 23 24 25 26 27 28     19 20 21 22 23 24 25     19 20 21 22 23 24 25
29 30 31                 26 27 28                 26 27 28 29 30 31

abril                     mayo                    junio
1         1  2  3  4  5  6                  1  2  3
2  3  4  5  6  7  8      7  8  9 10 11 12 13      4  5  6  7  8  9 10
9 10 11 12 13 14 15     14 15 16 17 18 19 20     11 12 13 14 15 16 17
16 17 18 19 20 21 22     21 22 23 24 25 26 27     18 19 20 21 22 23 24
23 24 25 26 27 28 29     28 29 30 31              25 26 27 28 29 30
30

julio                    agosto                 septiembre
1            1  2  3  4  5                     1  2
2  3  4  5  6  7  8      6  7  8  9 10 11 12      3  4  5  6  7  8  9
9 10 11 12 13 14 15     13 14 15 16 17 18 19     10 11 12 13 14 15 16
16 17 18 19 20 21 22     20 21 22 23 24 25 26     17 18 19 20 21 22 23
23 24 25 26 27 28 29     27 28 29 30 31           24 25 26 27 28 29 30
30 31

octubre                 noviembre                diciembre
1  2  3  4 15 16 17      1  2  3  4  5  6  7            1  2  3  4  5
18 19 20 21 22 23 24      8  9 10 11 12 13 14      6  7  8  9 10 11 12
25 26 27 28 29 30 31     15 16 17 18 19 20 21     13 14 15 16 17 18 19
22 23 24 25 26 27 28     20 21 22 23 24 25 26
29 30                    27 28 29 30 31

As can be seen, a Real Programmer has many intricacies to deal with!

## uBasic/4tH

The required "Snoopy" code is here. Use it when you feel like it.

Print "                      XXXX"
Print " X XX"
Print " X *** X XXXXX"
Print " X ***** X XXX XX"
Print " XXXX ******* XXX XXXX XX"
Print " XX X ****** XXXXXXXXX XX XXX"
Print " XX X **** X X** X"
Print " X XX XX X X***X"
Print " X //XXXX X XXXX"
Print " X // X XX"
Print " X // X XXXXXXXXXXXXXXXXXX/"
Print " X XXX// X X"
Print " X X X X X"
Print " X X X X X"
Print " X X X X X XX"
Print " X X X X X XXX XX"
Print " X XXX X X X X X X"
Print " X X X XX X XXXX"
Print " X X XXXXXXXX\\ XX XX X"
Print " XX XX X X X XX"
Print " XX XXXX XXXXXX/ X XXXX"
Print " XXX XX*** X X"
Print " XXXXXXXXXXXXX * * X X"
Print " *---* X X X"
Print " *-* * XXX X X"
Print " *- * XXX X"
Print " *- *X XXX"
Print " *- *X X XXX"
Print " *- *X X XX"
Print " *- *XX X X"
Print " * *X* X X X"
Print " * *X * X X X"
Print " * * X** X XXXX X"
Print " * * X** XX X X"
Print " * ** X** X XX X"
Print " * ** X* XXX X X"
Print " * ** XX XXXX XXX"
Print " * * * XXXX X X"
Print " * * * X X X"
Print " =======******* * * X X XXXXXXXX\\"
Print " * * * /XXXXX XXXXXXXX\\ )"
Print " =====********** * X ) \\ )"
Print " ====* * X \\ \\ )XXXXX"
Print " =========********** XXXXXXXXXXXXXXXXXXXXXX"

This is the code that generates the calendar:

Input "Year to print: "; Y             ' input required year

Push 63 : Gosub _Space ' center year
Print Y

For M = 1 To 7 Step 6 ' two rows of six months
Print

For C = 0 To 5 ' print months
Push 1, M + C, Y : Gosub _FnMjd : @(C+6) = Pop()

Push 5 : Gosub _Space ' print month name
Gosub (M + C)

If C = 5 Then ' is it the last month?
Print ' if so, terminate line
Else ' if not, print eight spaces
Push 8 : Gosub _Space
EndIf
Next

For C = 0 To 5 ' print days header
Print "Su Mo Tu We Th Fr Sa";

If C = 5 Then ' is it the last month?
Print ' if so, terminate line
Else ' if not, print two spaces
Push 2 : Gosub _Space
EndIf
' get days/month
Push M + C, Y : Gosub _FnDim : @(C+12) = Pop()
@(C) = 1 ' initialize array while we're at it
Next

C = 0 ' no columns printed yet
Q = 0 ' keep track of position

Do ' get day of the week
Push @(C+6) : Gosub _FnDow : Z = Pop ()

If @(C) - 1 < @(C + 12) Then
' if a position requested BEFORE
If (Z*3 + C*22) < Q Then ' the current position
Print ' then terminate the line
Q = 0 ' and reset the counter
Endif
' goto required position on screen
Push (Z*3 + C*22) - Q : Gosub _Space
Q = Z*3 + C*22 ' set counter to that position

If @(C) < 10 Then ' if only one digit date
Print " "; ' then compensate
Endif

Print @(C); ' print the date
Q = Q + 2 ' and update the position

@(C) = @(C) + 1
@(C+6) = @(C+6) + 1
Endif
' increment columns,
If (Z = 6) + (@(C)>@(C+12)) Then ' wrap around if required
C = (C + 1) % 6
EndIf
' loop until all dates are printed
Until (@(0)>@(0+12))*(@(1)>@(1+12))*(@(2)>@(2+12))*(@(3)>@(3+12))*(@(4)>@(4+12))*(@(5)>@(5+12))
Loop

Print ' terminate row with LF
Next

End

' convert D/M/Y to Julian date
_FnMjd ' (day month year -- julian date)
R = Pop() ' pop year
S = Pop() - 3 ' pop month
T = Pop() ' pop day

If S < 0 Then ' if month negative
S = S + 12 ' add 12 months
R = R - 1 ' and subtract a year
Endif

Push T + (153*S+2)/5 + R*365 + R/4 - R/100 + R/400 - 678882
Return

' calculate day of the week
_FnDow ' (julian -- day-of-week)
Push (Pop()+2400002)%7 ' convert julian date to day of week
Return

' calculate days in month
_FnDim ' (month year -- #days)
R = Pop() ' pop year
S = Pop() ' pop month

If S = 2 Then ' if February, get no. days
Push 28 + ((R%4)=0) - ((R%100)=0) + ((R%400)=0)
Else ' otherwise, either 30 or 31
If (S = 4) + (S = 6) + (S = 9) + (S = 11) Then
Push 30
Else
Push 31
Endif
Endif
Return

' print a number of spaces
_Space ' (#spaces --)
For X = 1 To Pop() ' print n spaces
Print " ";
Next
Return

' month name subroutines
001 Print " January "; : Return ' all have a fixed length
002 Print " February"; : Return ' which simplifies things
003 Print " March "; : Return
004 Print " April "; : Return
005 Print " May "; : Return
006 Print " June "; : Return
007 Print " July "; : Return
008 Print " August "; : Return
009 Print "September"; : Return
010 Print " October "; : Return
011 Print " November"; : Return
012 Print " December"; : Return

Output (missing Snoopy):

Year to print: 1969
1969

January               February               March                 April                  May                  June
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1                     1         1  2  3  4  5               1  2  3   1  2  3  4  5  6  7
5  6  7  8  9 10 11   2  3  4  5  6  7  8   2  3  4  5  6  7  8   6  7  8  9 10 11 12   4  5  6  7  8  9 10   8  9 10 11 12 13 14
12 13 14 15 16 17 18   9 10 11 12 13 14 15   9 10 11 12 13 14 15  13 14 15 16 17 18 19  11 12 13 14 15 16 17  15 16 17 18 19 20 21
19 20 21 22 23 24 25  16 17 18 19 20 21 22  16 17 18 19 20 21 22  20 21 22 23 24 25 26  18 19 20 21 22 23 24  22 23 24 25 26 27 28
26 27 28 29 30 31     23 24 25 26 27 28     23 24 25 26 27 28 29  27 28 29 30           25 26 27 28 29 30 31  29 30
30 31

July                 August               September              October               November              December
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5                  1  2      1  2  3  4  5  6            1  2  3  4                     1      1  2  3  4  5  6
6  7  8  9 10 11 12   3  4  5  6  7  8  9   7  8  9 10 11 12 13   5  6  7  8  9 10 11   2  3  4  5  6  7  8   7  8  9 10 11 12 13
13 14 15 16 17 18 19  10 11 12 13 14 15 16  14 15 16 17 18 19 20  12 13 14 15 16 17 18   9 10 11 12 13 14 15  14 15 16 17 18 19 20
20 21 22 23 24 25 26  17 18 19 20 21 22 23  21 22 23 24 25 26 27  19 20 21 22 23 24 25  16 17 18 19 20 21 22  21 22 23 24 25 26 27
27 28 29 30 31        24 25 26 27 28 29 30  28 29 30              26 27 28 29 30 31     23 24 25 26 27 28 29  28 29 30 31
31                                                                30

0 OK, 0:2753

## UNIX Shell

All Unix variations come with the cal command which makes the task very easy.

#!/bin/sh
echo "Snoopy goes here"
cal 1969

Output produced:

Snoopy goes here
1969

January               February               March
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1                     1
5  6  7  8  9 10 11   2  3  4  5  6  7  8   2  3  4  5  6  7  8
12 13 14 15 16 17 18   9 10 11 12 13 14 15   9 10 11 12 13 14 15
19 20 21 22 23 24 25  16 17 18 19 20 21 22  16 17 18 19 20 21 22
26 27 28 29 30 31     23 24 25 26 27 28     23 24 25 26 27 28 29
30 31
April                  May                   June
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5               1  2  3   1  2  3  4  5  6  7
6  7  8  9 10 11 12   4  5  6  7  8  9 10   8  9 10 11 12 13 14
13 14 15 16 17 18 19  11 12 13 14 15 16 17  15 16 17 18 19 20 21
20 21 22 23 24 25 26  18 19 20 21 22 23 24  22 23 24 25 26 27 28
27 28 29 30           25 26 27 28 29 30 31  29 30

July                 August              September
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4  5                  1  2      1  2  3  4  5  6
6  7  8  9 10 11 12   3  4  5  6  7  8  9   7  8  9 10 11 12 13
13 14 15 16 17 18 19  10 11 12 13 14 15 16  14 15 16 17 18 19 20
20 21 22 23 24 25 26  17 18 19 20 21 22 23  21 22 23 24 25 26 27
27 28 29 30 31        24 25 26 27 28 29 30  28 29 30
31
October               November              December
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
1  2  3  4                     1      1  2  3  4  5  6
5  6  7  8  9 10 11   2  3  4  5  6  7  8   7  8  9 10 11 12 13
12 13 14 15 16 17 18   9 10 11 12 13 14 15  14 15 16 17 18 19 20
19 20 21 22 23 24 25  16 17 18 19 20 21 22  21 22 23 24 25 26 27
26 27 28 29 30 31     23 24 25 26 27 28 29  28 29 30 31
30

## Vedit macro language

This implementation uses the calendar.vdm macro that comes with Vedit. (So it serves as an example of how to call other macros from a macro.) See CALENDAR task for a stand-alone version.
Calendar.vdm draws one month calendar. That is then copied as columnar block and pasted to the 1969 calendar.

Buf_Switch(Buf_Free)
Config_Tab(5,30,55)
#9 = 1 // first day of week: 0=Su, 1=Mo
#3 = 3 // number of months per line
#2 = 1969 // year
#1 = 1 // starting month
Repeat(12/#3) {
Repeat (#3) {
Buf_Switch(Buf_Free)
Call_File(122, "calendar.vdm", "DRAW_CALENDAR")
Reg_Copy_Block(10, 1, EOB_Pos, COLSET, 1, 21)
Buf_Quit(OK)
EOL Ins_Char(9)
#5 = Cur_Pos
Reg_Ins(10)
Goto_Pos(#5)
#1++
}
EOF
Ins_Newline(2)
}

The code above creates calendar for 80x43 display. For 132 column display, change #3 (number of months per line) to 4 or 6, and adjust the tab positions if required. The following would work with all widhts, but the left/right margin would not be balanced.

Config_Tab(22)

Output:

January   1969           February  1969           March     1969

Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su
--------------------     --------------------     --------------------
1  2  3  4  5                     1  2                     1  2
6  7  8  9 10 11 12      3  4  5  6  7  8  9      3  4  5  6  7  8  9
13 14 15 16 17 18 19     10 11 12 13 14 15 16     10 11 12 13 14 15 16
20 21 22 23 24 25 26     17 18 19 20 21 22 23     17 18 19 20 21 22 23
27 28 29 30 31           24 25 26 27 28           24 25 26 27 28 29 30
31

April     1969           May       1969           June      1969

Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su
--------------------     --------------------     --------------------
1  2  3  4  5  6               1  2  3  4                        1
7  8  9 10 11 12 13      5  6  7  8  9 10 11      2  3  4  5  6  7  8
14 15 16 17 18 19 20     12 13 14 15 16 17 18      9 10 11 12 13 14 15
21 22 23 24 25 26 27     19 20 21 22 23 24 25     16 17 18 19 20 21 22
28 29 30                 26 27 28 29 30 31        23 24 25 26 27 28 29
30

July      1969           August    1969           September 1969

Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su
--------------------     --------------------     --------------------
1  2  3  4  5  6                  1  2  3      1  2  3  4  5  6  7
7  8  9 10 11 12 13      4  5  6  7  8  9 10      8  9 10 11 12 13 14
14 15 16 17 18 19 20     11 12 13 14 15 16 17     15 16 17 18 19 20 21
21 22 23 24 25 26 27     18 19 20 21 22 23 24     22 23 24 25 26 27 28
28 29 30 31              25 26 27 28 29 30 31     29 30

October   1969           November  1969           December  1969

Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su
--------------------     --------------------     --------------------
1  2  3  4  5                     1  2      1  2  3  4  5  6  7
6  7  8  9 10 11 12      3  4  5  6  7  8  9      8  9 10 11 12 13 14
13 14 15 16 17 18 19     10 11 12 13 14 15 16     15 16 17 18 19 20 21
20 21 22 23 24 25 26     17 18 19 20 21 22 23     22 23 24 25 26 27 28
27 28 29 30 31           24 25 26 27 28 29 30     29 30 31

## XPL0

include c:\cxpl\codes;          \intrinsic 'code' declarations

func WeekDay(Year, Month, Day); \Return day of week (0=Sun 1=Mon..6=Sat)
int Year, Month, Day; \Works for years from 1583 onward
[if Month<=2 then [Month:= Month+12; Year:= Year-1];
return rem((Day-1 + (Month+1)*26/10 + Year + Year/4 + Year/100*6 + Year/400)/7);
];

proc Space(N); \Display N space characters
int N;
while N do [ChOut(0, ^ ); N:= N-1];

proc Calendar(Year); \Display calendar for specified year
int Year;
int Month, Col, C, Line, MoName, Days, DayMax, Day(3);
[MoName:= [
" January ", " February", " March ", " April ", " May ", " June ",
" July ", " August ", "September", " October", " November", " December"];
Space(35); Text(0, "[Snoopy]"); CrLf(0);
Space(37); IntOut(0, Year); CrLf(0);
CrLf(0);
for Month:= 1 to 12 do
[for Col:= 0 to 3-1 do
[Space(5); Text(0, MoName(Month+Col-1)); Space(7);
if Col<2 then Space(8);
];
CrLf(0);
for Col:= 0 to 3-1 do
[Text(0, "Su Mo Tu We Th Fr Sa");
if Col<2 then Space(9);
];
CrLf(0);
for Col:= 0 to 3-1 do \day of first Sunday of month (can be negative)
Day(Col):= 1 - WeekDay(Year, Month+Col, 1);
for Line:= 0 to 6-1 do
[for Col:= 0 to 3-1 do
[Days:= [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
DayMax:= Days(Month+Col);
if Month+Col=2 & (rem(Year/4)=0 & rem(Year/100)#0 ! rem(Year/400)=0) then
DayMax:= DayMax+1; \if February and leap year then add a day
for C:= 0 to 7-1 do
[if Day(Col)>=1 & Day(Col)<=DayMax then
[IntOut(0, Day(Col));
if Day(Col)<10 then Space(1); \left justify
]
else Space(2); \suppress out of range days
Space(1);
Day(Col):= Day(Col)+1;
];
if Col<2 then Space(8);
];
CrLf(0);
];
CrLf(0);
Month:= Month+2; \2+1 months per Col(umn)
];
];

Calendar(1969)
Output:
[Snoopy]
1969

January                      February                      March
Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa
1  2  3  4                            1                            1
5  6  7  8  9  10 11         2  3  4  5  6  7  8          2  3  4  5  6  7  8
12 13 14 15 16 17 18         9  10 11 12 13 14 15         9  10 11 12 13 14 15
19 20 21 22 23 24 25         16 17 18 19 20 21 22         16 17 18 19 20 21 22
26 27 28 29 30 31            23 24 25 26 27 28            23 24 25 26 27 28 29
30 31

April                         May                          June
Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa
1  2  3  4  5                      1  2  3          1  2  3  4  5  6  7
6  7  8  9  10 11 12         4  5  6  7  8  9  10         8  9  10 11 12 13 14
13 14 15 16 17 18 19         11 12 13 14 15 16 17         15 16 17 18 19 20 21
20 21 22 23 24 25 26         18 19 20 21 22 23 24         22 23 24 25 26 27 28
27 28 29 30                  25 26 27 28 29 30 31         29 30

July                        August                     September
Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa
1  2  3  4  5                         1  2             1  2  3  4  5  6
6  7  8  9  10 11 12         3  4  5  6  7  8  9          7  8  9  10 11 12 13
13 14 15 16 17 18 19         10 11 12 13 14 15 16         14 15 16 17 18 19 20
20 21 22 23 24 25 26         17 18 19 20 21 22 23         21 22 23 24 25 26 27
27 28 29 30 31               24 25 26 27 28 29 30         28 29 30
31

October                     November                     December
Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa         Su Mo Tu We Th Fr Sa
1  2  3  4                            1             1  2  3  4  5  6
5  6  7  8  9  10 11         2  3  4  5  6  7  8          7  8  9  10 11 12 13
12 13 14 15 16 17 18         9  10 11 12 13 14 15         14 15 16 17 18 19 20
19 20 21 22 23 24 25         16 17 18 19 20 21 22         21 22 23 24 25 26 27
26 27 28 29 30 31            23 24 25 26 27 28 29         28 29 30 31
30

## zkl

Gregorian calender only. Hard coded to a fit on a 80x43 terminal (somewhat half assed).

var [const] D=Time.Date, days="Su Mo Tu We Th Fr Sa";

fcn center(text,m) { String(" "*((m-text.len())/2),text) }

fcn oneMonth(year,month){
day1:=D.zeller(year,month,1); //1969-1-1 -->3 (Wed, ISO 8601)
dayz:=D.daysInMonth(year,month); //1969-1 -->31
List(center(D.monthNames[month],days.len()),days).extend(
(1).pump(dayz,(0).pump(day1,List,T(Void,""))).apply("%2s ".fmt)
.pump(List,T(Void.Read,days.len()/3,False),String.create));
}

const M=70; // mystery number
fcn oneYear(y,title){
println(center(title,M),"\n",center(y.toString(),M),"\n");
[1..12,3].pump(String,'wrap(m){ // 3 months per line
mmm:=(m).pump(3,List,oneMonth.fp(y)); //L(L(7-8 lines), L(...), L(...))
if(mmm.apply("len").sum() % 3) // months have diff # of lines, pad
mmm=mmm.apply("append","");
Utils.zipWith("%-25s%-25s%-25s\n".fmt,
mmm.xplode()).concat() + (if (m<D.October) "\n" else "")
})
}

oneYear(1969,"3 Days of Peace & Music").println();

oneMonth produces a list of strings that make up a one month calender. Each day is three characters, the first line is padded with blanks to line it up with the 1st day of the week. The entire month is one long list of "days" that is then chunked into a list of weeks (one line per week). oneYear takes 3 months and builds the page line by line.

Output:
3 Days of Peace & Music
1969

January                  February                  March
Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa
1  2  3  4                        1                        1
5  6  7  8  9 10 11      2  3  4  5  6  7  8      2  3  4  5  6  7  8
12 13 14 15 16 17 18      9 10 11 12 13 14 15      9 10 11 12 13 14 15
19 20 21 22 23 24 25     16 17 18 19 20 21 22     16 17 18 19 20 21 22
26 27 28 29 30 31        23 24 25 26 27 28        23 24 25 26 27 28 29
30 31

April                     May                      June
Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa
1  2  3  4  5                  1  2  3      1  2  3  4  5  6  7
6  7  8  9 10 11 12      4  5  6  7  8  9 10      8  9 10 11 12 13 14
13 14 15 16 17 18 19     11 12 13 14 15 16 17     15 16 17 18 19 20 21
20 21 22 23 24 25 26     18 19 20 21 22 23 24     22 23 24 25 26 27 28
27 28 29 30              25 26 27 28 29 30 31     29 30

July                    August                 September
Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa
1  2  3  4  5                     1  2         1  2  3  4  5  6
6  7  8  9 10 11 12      3  4  5  6  7  8  9      7  8  9 10 11 12 13
13 14 15 16 17 18 19     10 11 12 13 14 15 16     14 15 16 17 18 19 20
20 21 22 23 24 25 26     17 18 19 20 21 22 23     21 22 23 24 25 26 27
27 28 29 30 31           24 25 26 27 28 29 30     28 29 30
31

October                  November                 December
Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa     Su Mo Tu We Th Fr Sa
1  2  3  4                        1         1  2  3  4  5  6
5  6  7  8  9 10 11      2  3  4  5  6  7  8      7  8  9 10 11 12 13
12 13 14 15 16 17 18      9 10 11 12 13 14 15     14 15 16 17 18 19 20
19 20 21 22 23 24 25     16 17 18 19 20 21 22     21 22 23 24 25 26 27
26 27 28 29 30 31        23 24 25 26 27 28 29     28 29 30 31
30