protected function getDefaultPattern()
    {
        $patternParts = [];
        if (self::NONE !== $this->datetype) {
            $patternParts[] = $this->defaultDateFormats[$this->datetype];
        }
        if (self::NONE !== $this->timetype) {
            $patternParts[] = $this->defaultTimeFormats[$this->timetype];
        }

        return implode(', ', $patternParts);
    }