    public function format($date, $format)
    {
        if ($date instanceof \DateTimeInterface) {
            return $date->format($format);
        } elseif ($date instanceof \DateInterval) {
            return $date->format($format);
        } elseif ($date === 'now') {
            return date($format);
        } else {
            $timestamp = (integer)$date;
            return date($format, $timestamp);
        }
    }