date « MemoSoup

Unix: get the file date

ls -1 | cpio -o | cpio -ivt | awk ‘{print $NF, $(NF-1), $(NF-4), $(NF-3) }’

Warning: I/O expensive for the large files!

Perl:

@a = localtime((stat($my_file))[9]); [...]

The easiest way is to use specialized package (like Date::Calc).
If You need standalone function, the following method could be used.

#!/usr/bin/perl

$year=$ARGV[ 0 ];
$isJulian=(defined($ARGV[ 1 ]) && $ARGV[ 1 ] eq ‘julian’);
$isOrthodox=(defined($ARGV[ 1 ]) && $ARGV[ 1 ] eq ‘orthodox’);

my ( $G , $C , $H, $I, $J , $L );

$G = $year % 19 ;
if ( $isJulian [...]