- var_dump: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
var_dump(
date('U', strtotime('2017-07-12 12:54:00')),
date('U', strtotime('2017-07-12T12:54:00')),
date('U', strtotime('12/07/2017 12:54:00')),
date('U', strtotime('12/07/2017T12:54:00'))
);