Elastica\Aggregation\DateHistogram::setFormat PHP Метод

    public function setFormat($format)
    {
        return $this->setParam('format', $format);
    }

 private function getDatedStatsQuery($journal)
 {
     $filter = new Term();
     $filter->setTerm('journalUsers.journal.id', $journal->getId());
     $filterQuery = new Query\Filtered();
     $filterQuery->setFilter($filter);
     $query = new Query($filterQuery);
     $dateHistogram = new DateHistogram('dateHistogram', 'created', 'month');
     $dateHistogram->setFormat("YYYY-MM-dd");
     $query->addAggregation($dateHistogram);
     $query->setSize(0);
     return $query;
 }