Shell Programming and Scripting

T1=$(date +%s -d "Mon Dec 31 16:00:01 PST 2015")
T2=$(date +%s -d "Tue Mar 19 06:09:30 PDT 2013")
DAYS=$(((T1-T2)/(60*60*24)))

#!/usr/bin/perl
 
use strict;
use Time::Piece;
use POSIX qw(strftime);
 
 
my $before = Time::Piece->strptime("Tue Mar 19 06:09:30 PDT 2013", "%a %b %d %H:%M:%S %Z %Y");
my $after  = Time::Piece->strptime("Mon Dec 31 16:00:01 PST 2015", "%a %b %d %H:%M:%S %Z %Y");


# Gap in seconds
my $secdiff = int ($after - $before);
 
 
# Format the result .
print  strftime( '%H:%M:%S', gmtime($secdiff))."\n";