- var_dump: documentation ( source)
<?php
$s = new \DateTime('2016-03-01', new \DateTimeZone('Europe/Warsaw'));
$e = new \DateTime('2016-03-31', new \DateTimeZone('Europe/Warsaw'));
$d = $s->diff($e);
var_dump($d);
$s = new \DateTime('2016-05-01', new \DateTimeZone('Europe/Warsaw'));
$e = new \DateTime('2016-05-31', new \DateTimeZone('Europe/Warsaw'));
$d = $s->diff($e);
var_dump($d);
$s = new \DateTime('2016-04-01', new \DateTimeZone('Europe/Warsaw'));
$e = new \DateTime('2016-04-30', new \DateTimeZone('Europe/Warsaw'));
$d = $s->diff($e);
var_dump($d);