Description:
------------
a bug(?) in the time() function

Reproduce code:
---------------
    function isInt($string) {
        $string = preg_replace('[0-9]','',$string);
        if($string == '') {
            return true;
        } else {
            return false;
        }
    }

    if(isInt(time())) {
        echo "is Int";
    } else {
        echo "is not Int";
    }

Expected result:
----------------
is Int

Actual result:
--------------
is not Int