- preg_match: documentation ( source)
- date: documentation ( source)
- preg_replace: documentation ( source)
<?php
$url='http://checkerproxy.net/ru/date("Y-m-d")';
if(preg_match('/date\(\"(.*?)\"\)/i', $url, $mdate)){
echo preg_replace('/date\(\"(.*?)\"\)/i', date($mdate[1]), $url);
}