$minutes_to_add = 5; $time = new DateTime('2011-11-17 05:05'); $time->add(new DateInterval('PT' . $minutes_to_add . 'M')); $stamp = $time->format('Y-m-d H:i');
date('Y-m-d H:i',strtotime('+1 hour +20 minutes',strtotime($start)));