protected function doesNumFmtIdIndicateDate($numFmtId)
    {
        if (!isset($this->numFmtIdToIsDateFormatCache[$numFmtId])) {
            $formatCode = $this->getFormatCodeForNumFmtId($numFmtId);

            $this->numFmtIdToIsDateFormatCache[$numFmtId] = (
                $this->isNumFmtIdBuiltInDateFormat($numFmtId) ||
                $this->isFormatCodeCustomDateFormat($formatCode)
            );
        }

        return $this->numFmtIdToIsDateFormatCache[$numFmtId];
    }