#$end=timegm(gmtime());
#should be
$end_secs=timegm(gmtime());
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D'oh! Thanks.

That still doesn't seem correct, as I'm getting a difference of around 750 hours.

You have a difference of 750 hours. Have you looked at the expected time difference?

Maybe you want to study again the exact ranges of allowed input parameters for Time::Local. Especially re-read the second paragraph of the description, where the documentation draws particular attention to the allowed values for the month.

Maybe you want to try the following dates and study the error message you get

2013-02-31
2013-01-28
2013-01-29
2013-01-30
2013-01-31
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<Reveal this spoiler or all in this thread>

At a first glance, this DateTime::Format::ISO8601 should be helpful. Probably this as well: ISO 8601...

Update: Here is some sample code

use strict;
use warnings;
use DateTime::Format::ISO8601;

my $str = '2013-10-28T18:59:52.863Z';
my $dt  = DateTime::Format::ISO8601->parse_datetime( $str );
my $now = DateTime->now;

print +($dt->epoch() - $now->epoch())/3600, " hours\n";
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that is perfect!

Hi,
You might try DateTime module and one of the math method, for example :$dt->delta_ms( $datetime )

#!/usr/bin/perl
use strict;
use warnings;
use DateTime;

my $now = DateTime->now;
$now->iso8601;            
$now->subtract( seconds => 101 )->iso8601;
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Update: piece of code

hth,
PooLpi

use strict;
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During development, always

use warnings;
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Some will argue warningsshould stay in production code; I disagree but this is a local decision anyway.

Date::Manip, Date::Calc, a search of http://search.cpan.org for the keyword, "date."

Get to know CPAN very well. If you actually had to "start from scratch" to do most things, Perl would be nothing-special. Even if you can't easily install a module, you can always look at the source-code to it on the website to see precisely how the trick is done.

You can do this with the builtin module Time::Piece:

#!/usr/bin/env perl -l

use strict;
use warnings;

use Time::Piece;

my $start = '2013-10-28T18:59:52.863Z';
my ($whole, $ms) = $start =~ /([^.]+)(.*)Z$/;
my $t1 = Time::Piece->strptime($whole => '%Y-%m-%dT%H:%M:%S');

my $t2 = gmtime;

my $diff = $t2 - $t1;

print 'Whole seconds diff: ', $diff;
print 'Fractional seconds diff: ', $diff - $ms;
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Output (which is correct for my timezone):

Whole seconds diff: 46979
Fractional seconds diff: 46978.137
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My UTC date/time:

$ date -u
Tue 29 Oct 2013 08:02:51 UTC
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Confirmation calculation:

$ perl -E 'say(5*60*60 + 8 + 8*60*60 + 2*60 + 51)'
46979
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