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

#InputFormat: JJJJ.MM.DD-HH:MM:SS
my $date=shift(@ARGV) // '2005.02.25-00:00:00';
my @date=$date=~/^\s*(\d{,4})\.(\d{,2})\.(\d{,2})(?:-(\d{,2}):(\d{,2}):(\d{,2}))$/;
push(@date,0)while(@date<6);
$date[0]+=1900 if(length($date[0])<3);
$date[1]=1 if($date[1]<1);
$date[2]=1 if($date[2]<1);


my $past = DateTime->new(
    year => shift(@date),
    month => shift(@date),
    day => shift(@date),
    hour => shift(@date),
    minute => shift(@date),
    time_zone => 'Europe/Berlin',
  );
my $jetzt = DateTime->now();
my $delta = $jetzt->subtract_datetime_absolute($past);
print $delta->in_units( 'seconds' );

SET diff=0
FOR /F "options" %%I IN (`perl delta.pl -- 2010:10:10-10.10.10`) DO SET diff=%%I
"C:\Program Files\VirtualBox\VBoxManage.exe" modifyvm "Beta-VM" --biossystemtimeoffset %diff%