- print_r: documentation ( source)
- date_default_timezone_set: documentation ( source)
<?php
date_default_timezone_set("Europe/Vilnius");
$datetime1 = new DateTime('1970-01-01 11:55:00');
$datetime2 = new DateTime('2014-01-29 11:55:00');
$interval = $datetime1->diff($datetime2);
print_r($interval);
?>