- var_dump: documentation ( source)
- mktime: documentation ( source)
- date: documentation ( source)
<?php
$s = mktime(0,1,0);
var_dump($s);
var_dump(date('d-m-Y h:i:s', $s));//this is 12-hour format
var_dump(date('d-m-Y H:i:s', $s));//this is 24-hour format