- mktime: documentation ( source)
- date_default_timezone_set: documentation ( source)
<?php
date_default_timezone_set('Europe/Berlin'); # timezone with DST
echo mktime(0, 0, 0, 10, 28, 2014), "\n"; #1414450800 for PHP versions 5.1.0 - 5.5.8
echo mktime(0, 0, 0, 10, 14, 2014), "\n";