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];
}