protected function getIsExpired(Document $document) 
	{
		$date = null === $document->getDateEdit() ? $document->getDateInsert() : $document->getDateEdit();
		$now = new \Datetime("now");
		$interval = $date->diff($now);
		
		if ($interval->y > 0) {
			return true;
		}
		
		return $interval->m >= 6;
	}