And what should happen? You try this:

<?php

$date = date("Y-m-d");

if (ereg ("([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})", $date, $regs)) {
    echo "$regs[3].$regs[2].$regs[1]";
} else {
    echo "Invalid date format: $date";
}   

?>

Works for me just fine.