How to get time difference in perl? - perl

Question

I have two strings which contain time stamps only and look like this - my $t = "2014-11-28 00:00:00.000"; How do I get the time difference between then in readable time (days, hours, minutes, seconds) and not seconds. I am new and I am facing great difficulty in doing this. Each blog or article is telling me to do different things. Some things can't be done because I don't have the modules. I cannot even install the modules into perl because I have many pearl versions on the computer I am working on. So, cpan > install some::modlue does not help.
Please teach me how to do this. Please try to use core perl. Otherwise I will have to spend more time in installing perl modules into the right perl
I made some code to begin with, but its wrong and useless -
use strict;
use warnings;
use Time::Local;
sub secondsToTime{
my $inSeconds = shift;
my $days = int($inSeconds/(24*60*60));
my $hours = ($inSeconds/(60*60))%24;
my $mins = ($inSeconds/60)%60;
my $sec = $inSeconds%60;
my $time = "$days days, $hours hours, $mins mins, $sec seconds";
return $time;
}
# EXAMPLE timelocal( $sec, $min, $hour, $mday, $mon, $year );
my #today = localtime();
print "#today\n";
my $currentTime = timelocal(#today);
#my #t = (0, 00, 13, 28, 11, 2014);
#$currentTime = timelocal(#t);
my #birthday = (0, 00, 12, 28, 11, 2014);
my $birthTime = timelocal(#birthday);
my $sec = ($currentTime - $birthTime);
my $time = secondsToTime($sec);
print "My age = $time\n";

Answer 1

You don't seem to want to help us understand what it is you need.
This program will print the difference between 2014-11-28T00:00:00.000Z and 2014-11-28T00:00:00.000Z.
use strict;
use warnings;
use Time::Piece;
my $start = '2014-11-28T00:00:00.000Z';
my $end = '2014-11-28T00:00:00.000Z';
print difference($start, $end);
sub difference {
my ($beg, $end) = map Time::Piece->strptime(s/\.\d*Z?\z//r, '%Y-%m-%dT%H:%M:%S'), #_;
($end-$beg)->pretty;
}
output
0 seconds