- var_dump: documentation ( source)
<?php
$dt = new DateTime(1234567890);
var_dump($dt->getTimestamp());
var_dump($dt->format("Y-m-d H:i:s"));
$dt = DateTime::createFromFormat("U", 1234567890);
var_dump($dt->getTimestamp());
var_dump($dt->format("Y-m-d H:i:s"));