- var_dump: documentation ( source)
<?php
$start = DateTime::createFromFormat('U', 1347577200);
$end = DateTime::createFromFormat('U', 1347580800);
$diff = $start->diff($end);
print 'Diff: '.$diff->h.' hours, '.$diff->i.' minutes<br>';
$interval = DateInterval::createFromDateString('30 minutes');
var_dump($interval);
$end->add($interval);
$diff = $start->diff($end);
print '<br>Diff after interval: '.$diff->h.' hours, '.$diff->i.' minutes';
?>