- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$prazo = date('Y-m-d', strtotime(date('Y-m-d h:i').' - 30 days'));
$criacao = date('2013-08-04 10:17:00');
print $prazo.' | '.$criacao;
if ($prazo >= $criacao) {
print "Prazo maior";
} else {
print "Prazo menor";
}