- var_dump: documentation ( source)
- min: documentation ( source)
<?php
var_dump(min(NULL, false));
var_dump(min(0, false));
var_dump(min(false, 0));
var_dump(min(NULL, "2012-12-21"));
var_dump(min("2011-01-10", "2012-12-21"));
var_dump(min("2013-01-10", "2012-12-21"));
var_dump(min("2012-12-21", "2012-12-21 00:00:01"));
var_dump(min("2012-12-21", "2012-12-20 23:59:59"));