- var_dump: documentation ( source)
<?php
$dt = new DateTime('2014-01-05');
$interval = $dt->diff(new DateTime('2014-01-08'));
var_dump($interval->d);
$interval = $dt->diff(new DateTime('2014-01-05'));
var_dump($interval->d);
$interval = $dt->diff(new DateTime('2014-01-01'));
var_dump($interval->d);