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

my $val= "Aug 26 23:10:59";
$val =~ tr/:/ /;
my $val1="Aug 27 10:59:02";
$val1 =~ tr/:/ /;

my %MONTH_NAMES = ( "Jan" => '01',  "Feb"=> '02',  "Mar" => '03',
                        "Apr"=> '04',"May" => '05',  "Jun" => '06',
                        "Jul" => '07', "Aug" => '08',  "sep" => '09',
                       "oct" => '10', "Nov" => '11', "Dec" => '12' );

my $sysdate= `date`;
chomp($sysdate);
my $year=(split(/ /,$sysdate))[-1];

my($mon,$mday,$hour,$minute,$sec)=split(/ /,$val);
$time_1 = timelocal($sec,$minute,$hour,$mday,$mon,$year);
my($mon,$mday,$hour,$minute,$sec)=split(/ /,$val1);
$time_2 = timelocal($sec,$minute,$hour,$mday,$mon,$year);
print "1 :$time_1:\n";
print "2 :$time_2:\n";
$diff_time = $time_2 - $time_1;
print "diff_time :$diff_time:\n";


output : 
1 :1169824259:
2 :1169866742:
diff_time :42483: