Shell Programming and Scripting

#!/usr/bin/perl
use strict;
use warnings;
use Time::Local;

#always gmt
#my $tval = '2013-12-01T05:23:19.374';

my ($year,$month,$day,$hour,$min,$sec,$mil) = $ARGV[0] =~ m/^(\d{4})-(\d{1,2})-(\d{1,2})T(\d{1,2}):(\d{1,2}):(\d{1,2}).(\d{3})$/;
print "$year-$month-$day $hour:$min:$sec\n";
my $seconds = timelocal($sec, $min, $hour, $day, $month-1, $year);
($sec, $min, $hour,$day,$month, $year) = localtime($seconds-25200);

printf "%04d-%02d-%02d %02d:%02d:%02d", $year+1900, $month+1, $day, $hour, $min, $sec;

$ TZ=MST date -d "2013-12-01 05:23:19.374 GMT"
Sat Nov 30 22:23:19 MST 2013

#!/usr/bin/perl
use strict;
use warnings;
use Time::Local;
use POSIX qw{ strftime }

my @T = $ARGV[0] =~ m/^(\d{4})-(\d{1,2})-(\d{1,2})T(\d{1,2}):(\d{1,2}):(\d{1,2})(?:\.\d+)$/;
print strftime("%Y-%m-%d %H:%M:%S %Z%n", localtime timegmt reverse @T);

#!/usr/bin/perl
use strict;
use warnings;
use Time::Local;
use POSIX qw(tzset);

#always gmt
#my $tval = '2013-12-01T05:23:19.374';

my ($year,$month,$day,$hour,$min,$sec,$mil) = $ARGV[0] =~ m/^(\d{4})-(\d{1,2})-(\d{1,2})T(\d{1,2}):(\d{1,2}):(\d{1,2}).(\d{3})$/;
print "$year-$month-$day $hour:$min:$sec\n";
$ENV{TZ}="GMT";
tzset;
my $seconds = timelocal($sec, $min, $hour, $day, $month-1, $year);
$ENV{TZ}="MST";
tzset;
($sec, $min, $hour,$day,$month, $year) = localtime($seconds);

printf "%04d-%02d-%02d %02d:%02d:%02d\n", $year+1900, $month+1, $day, $hour, $min, $sec;