How can I split a string in PHP at the nth occurrence of a needle?

It could be:

function split2($string, $needle, $nth) {
    $max = strlen($string);
    $n = 0;
    for ($i=0; $i<$max; $i++) {
        if ($string[$i] == $needle) {
            $n++;
            if ($n >= $nth) {
                break;
            }
        }
    }
    $arr[] = substr($string, 0, $i);
    $arr[] = substr($string, $i+1, $max);

    return $arr;
}