protected function _getLastBuildDate($name, $aData)
    {
        if ($aData2 = Registry::getUtils()->fromFileCache($this->_getCacheId($name))) {
            $sLastBuildDate = $aData2['content']['lastBuildDate'];
            $aData2['content']['lastBuildDate'] = '';
            $aData['lastBuildDate'] = '';
            if (!strcmp(serialize($aData), serialize($aData2['content']))) {
                return $sLastBuildDate;
            }
        }

        return date('D, d M Y H:i:s O');
    }