- var_dump: documentation ( source)
<?php
$date1 = new DateTime("@1421352487"); // Sun Oct 28 2012 02:00:00 GMT+2 (DST)
var_dump($date1->getTimestamp()); //prints: 1351382400
$date1->setTimezone(new DateTimeZone("Europe/Stockholm"));
var_dump($date1->getTimestamp()); //prints: 1351386000