#! /usr/bin/perl -l
use strict; 
use warnings ;
use Time::Local qw(timegm_nocheck); 

my $time1 = '12:44:01';
my $time2 = '12:45:01';

print "diff is ".(timegm_nocheck(split/:/,$time2) - timegm_nocheck(split/:/,$time1)) ;