#!/usr/bin/perl

use Time::Local;

my $t1 = '31.10.2004 01:00';
my $t2 = '31.10.2004 00:40';

$t1 = time2epoch($t1);
$t2 = time2epoch($t2);

print "$t1 - $t2 = ", $t1 - $t2, "\n";

sub time2epoch {
  my $t = shift;

  my ($d, $m, $y, $H, $M) = split /[\.\s:]/, $t;

  --$m;
  $y -= 1900;                                

  return timegm 0, $M, $H, $d, $m, $y;
}