# 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.

## Contents

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, COURIERGui, add, edit, vYr w40 r1 Limit4 Number, 1969Gui, add, edit, vEdit2 w580 r38Gui, Add, Button, Default Hidden gSubmitGui, show Submit:Gui, Submit, NoHideGuiControl,, Edit2, % Calendar(Yr)return GuiEscape:GuiClose:ExitAppreturn
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                                           

 #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($sLine) Next NextEndFunc ;==>_CreateCalendar Func _PrintLine($_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 awkTo change the output width, change the value assigned to variable pagewide #!/bin/gawk -fBEGIN{ 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",$1) ) # January - December for (i=1; i<13; i++) { prmonth(i,newdow,monsize) newdow=(monsize+newdow) %7 if (newdow == 0) newdow = 7 monsize=substr(days,2+2*i,2) if (leap == 1 && monsize == 28) monsize = 29 } }  Output:  [ picture of Snoopy goes here ] 1969 January February March Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 5 6 7 8 9 10 11 2 3 4 5 6 7 8 2 3 4 5 6 7 8 12 13 14 15 16 17 18 9 10 11 12 13 14 15 9 10 11 12 13 14 15 19 20 21 22 23 24 25 16 17 18 19 20 21 22 16 17 18 19 20 21 22 26 27 28 29 30 31 23 24 25 26 27 28 23 24 25 26 27 28 29 30 31 April May June Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 3 1 2 3 4 5 6 7 6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14 13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21 20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28 27 28 29 30 25 26 27 28 29 30 31 29 30 July August September Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 5 1 2 1 2 3 4 5 6 6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13 13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20 20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27 27 28 29 30 31 24 25 26 27 28 29 30 28 29 30 31 October November December Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa 1 2 3 4 1 1 2 3 4 5 6 5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13 12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20 19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27 26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31 30  ## BBC BASIC The day and month names are in the language for which the PC is configured.  INSTALL @lib$+"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

## 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


## 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);    auto offs = cast(int)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

## 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 language 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 @abcUcalfill=' '; mc=12; _='1 3 1234567890' "fb"xparse 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 upperCaseparse arg mm '/' dd "/" yyyy _ '(' ops;  uops=opsif _\=='' | \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=1days='Sunday Monday Tuesday Wednesday Thursday Friday Saturday'months='January February March April May June July August September October November December'days=' 'days;  months=' 'monthscyyyy=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=76if small    then do; narrow=1   ; short=1   ; endif smaller  then do; narrower=1 ; shorter=1 ; endif smallest then do; narrowest=1; shortest=1; endif shortest then shorter=1if shorter  then short  =1if narrow    then do; cw=9; cindent=3; calwidth=69; endif narrower  then do; cw=4; cindent=1; calwidth=34; endif narrowest then do; cw=2; cindent=1; calwidth=20; endcv_=calwidth+calspaces+2calfill=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 fcalPutsreturn _ /*─────────────────────────────calGen subroutine────────────────────────*/calGen: cellX=;cellJ=;cellM=;calCells=0;calline=0call calPutcall calPutl copies('─',calwidth),"┌┐"; call calHdcall calPutl month ' ' _yyyy          ; call calHdif narrowest | narrower then call calPutl daysn                        else do jw=1 for 3                             if space(days.jw)\=='' then call calPutl days.jw                             endcalft=1; calfb=0  do jf=1 for dow-1; call cellDraw calFill,calFill; end  do jy=1 for dim; call cellDraw jy; endcalfb=1  do 7; call cellDraw calFill,calFill; endif sd>32 & \shorter then call calPutreturn /*─────────────────────────────cellDraw subroutine──────────────────────*/cellDraw: parse arg zz,cdDOY;zz=right(zz,2);calCells=calCells+1if 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                   endcdDOY=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')-1abbn: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; returncalCsm:if sd>24&\short then call calPutl cellM;if sd>49&\shorter then call calPutl cellB;returncalHd:if sd>24&\shorter then call calPutl;if sd>32&\shortest then call calPutl;returncalPb:if \grid&shortest then call put chk;returncalPut:calPuts=calPuts+1;maxKalPuts=max(maxKalPuts,calPuts);if symbol('CT.'calPuts)\=='VAR' then ct.calPuts=;ct.calPuts=overlay(arg(1),ct.calPuts,cv);returncalPutl:call calPut copies(' ',cindent)left(arg(2)"│",1)center(arg(1),calwidth)||right('│'arg(2),1);returncx: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_;returndow: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 wer:parse arg _1,_2;call '$ERR' "14"p(_1) p(word(_1,2) !fid(1)) _2;if _1<0 then return _1;exit resulterr: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;returnint:int=numx(arg(1),arg(2));if \isint(int) then call erx 92,arg(1) arg(2);return int/1is#:return verify(arg(1),#)==0isint: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 lyna:if arg(1)\=='' then call erx 01,arg(2);parse var ops na ops;if na=='' then call erx 35,_o;return nanai: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 fnumx: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 _;returntell:say arg(1);returnungrid: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. • This program requires Ruby 1.8.7 because it calls Array#each_slice. Works with: Ruby version 1.8.7 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 co)              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.postfixOpsimport 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



## 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]}]} snoopycal

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…

snoopycal 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:

snoopycal 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!

## UNIX Shell

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

 #!/bin/shecho "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 monthRepeat(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 charactersint  N;while N do [ChOut(0, ^ );  N:= N-1]; proc Calendar(Year);            \Display calendar for specified yearint  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   T(center(D.monthNames[month],days.len()),days).extend(      (1).pump(dayz,(0).pump(day1,T,T(Void,""))).apply("%2s ".fmt)      .pump(List,T(Void.Read,days.len()/3,False),String.create));} const M=70;	// mystery numberfcn 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