CDavAddressbookCrmBase::CatalogLastModifiedAt

protected function CatalogLastModifiedAt($collectionId = '', $filter = array())
{
	if (!empty($filter['XML_ID']))
	{
		unset($filter['XML_ID']);
	}
	$lastEditedEntity = $this->LoadCrmResourceEntitiesListByParams(array('DATE_MODIFY' => "DESC"), $filter, 1, array('DATE_MODIFY'));
	if ($entity = $lastEditedEntity->Fetch())
	{
		return $entity["DATE_MODIFY"];
	}
	return BitrixMainTypeDate::createFromTimestamp(0)->toString();
}