Days between dates: Difference between revisions

 

;Task:

 

 

 

To demonstrate one of the numerous ways this can be done.

 

 

=={{header|AWK}}==

# syntax: GAWK -f DAYS_BETWEEN_DATES.AWK

BEGIN {

return(result)

}

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<pre>

generic 2020-01-01 to 2020-03-01 = 60

</pre>

=={{header|Erlang}}==

 

-module(daysbetween).

 

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erlang shell:

</pre>

 

=={{header|Factor}}==

Factor supports the addition and subtraction of timestamps and durations with the <code>time+</code> and <code>time-</code> words.

 

: days-between ( ymd-str ymd-str -- n )

 

"2019-01-01" "2019-09-30" days-between .

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<pre>

273

</pre>

 

=={{header|Go}}==

 

import (

days = daysBetween(date1, date2)

fmt.Printf("There are %d days between %s and %s\n", days, date1, date2)

 

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There are 274 days between 2015-12-31 and 2016-09-30

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=={{header|Lua}}==

This uses os.difftime to compare two Epoch times. Not to be used with dates before 1970.

 

-- Convert date string as YYYY-MM-DD to Epoch time.

local d2 = parseDate(io.read())

local diff = math.ceil(os.difftime(d2, d1) / SECONDS_IN_A_DAY)

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<pre>Enter date 1: 1970-01-01

Enter date 2: 2019-10-02

There are 18171 days between these dates.</pre>

 

=={{header|Perl}}==

Would not reinvent this wheel.

use Date::Calc qw(Delta_Days);

 

say Delta_Days(2000,1,1, 2100,1,1); # another, with one extra leap day

say Delta_Days(2020,1,1, 2019,10,1); # backwards in time

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<pre>427

Date::Calc::PP::Delta_Days(): Date::Calc::Delta_Days(): not a valid date at Days_between_dates line 10</pre>

 

 

 

 

 

 

 

 

 

 

=={{header|Python}}==

 

#!/usr/bin/python

two = sys.argv[2]

print diff(one,two)

 

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272

</pre>

 

=={{header|REXX}}==

<br>days since the beginning of the Gregorian calendar, &nbsp; and &nbsp; '''I''' &nbsp; which is the option that indicates the date is in

<br>the &nbsp; '''ISO''' &nbsp; (International Standards Organization standard 8601:2004) &nbsp; format.

parse arg $1 $2 . /*get 2 arguments (dates) from the C.L.*/

say abs( date('B',$1,"I") - date('B',$2,"I") ) ' days between ' $1 " and " $2

{{out|output|text=&nbsp; when using the inputs of: &nbsp; &nbsp; <tt> 2019-10-02 &nbsp; 2000-01-01 </tt>}}

<pre>

</pre>

 

<br>allowing a single asterisk &nbsp; ('''*''') &nbsp; to be used for a date &nbsp; (which signifies that the current date is to be used).

 

 

Also, more informative error messages are generated.

parse arg $.1 $.2 _ . 1 . . xtra /*obtain two arguments from the C.L. */

?.1= '1st'

?.2= '2nd'

if _ \== '' then call err "too many arguments specified: " xtra

parse value 30 with dy.4 1 dy.6 1 dy.9 1 dy.11 /*define 30─day months, Feb. is special*/

 

do j=1 for 2 /*examine both dates for correct format*/

end /*j*/

 

/*──────────────────────────────────────────────────────────────────────────────────────*/

commas: parse arg _; do c_=length(_)-3 to 1 by -3; _=insert(',', _, c_); end; return _

err: say; say '***error*** ' arg(1); exit 13 /*issue an error message (with text) */

isDec: return verify( arg(1), 1234567890) \== 0 /*insure argument is just decimal digs.*/

{{out|output|text=&nbsp; when using the inputs of: &nbsp; &nbsp; <tt> * &nbsp; 2000-1-1 </tt>}}

 

Today &nbsp; (indicated by the asterisk) &nbsp; is &nbsp; 2019-10-2

<pre>

</pre>

 

=={{header|Ruby}}==

 

d1, d2 = Date.parse("2019-1-1"), Date.parse("2019-10-19")

p (d1 - d2).to_i # => -291

p (d2 - d1).to_i # => 291

 

=={{header|zkl}}==

today:=TD.parseDate("--"); // "yyyy-mm-dd" and variations --> (y,m,d)

// or Time.Clock.UTC --> (y,m,d,h,m,s)

TD.toYMDString(today.xplode()), // to(y,m,d) not to((y,m,d))

TD.toYMDString(then.xplode()),

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<pre>