3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = new DateTime('2014-01-01 10:25:00', new DateTimeZone('Europe/Madrid')); $b = new DateTime('2014-01-01 14:15:00', new DateTimeZone('Europe/Athens')); $diff = $b->getTimestamp() - $a->getTimestamp(); var_dump($diff);

preferences:
38.39 ms | 402 KiB | 5 Q