I had a similar problem with an application that had to return local times for multiple timezones. An easy enough way to do this is to use the DateTime module. To convert a known time to another time, you can use:

    my $oldDate = DateTime->new(month=>$monthVar,
                day=>$dayVar,
                year=>$yearVar,
                hour=>$hourVar,
                minute=>$minuteVar,
                time_zone=>'local');
    $dateObject = $oldDate->clone()->set_time_zone('UTC');
    $dateObject =~ s/T/ /;
    print &UnixDate($dateObject,"%m/%d/%Y %H:%M")
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In order to just get the current date/time in UTC format, you can use:

    $dateObject =  DateTime->now(time_zone=>'UTC');
    print $dateObject;
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