public static function initDatetimesInRange($start_datetime, $end_datetime, $hoursDifference = 1){
        $dates_in_range = [];
        $begin = new DateTime($start_datetime);
        $end = new DateTime($end_datetime);
        $endModify = $end->modify( '+'.$hoursDifference.' hour' ); 

        $interval = new DateInterval('PT'.$hoursDifference.'H');
        $daterange = new DatePeriod($begin, $interval ,$endModify);

        foreach($daterange as $date){
            $dates_in_range[$date->getTimestamp()] = $date->format("Y-m-d H:i:s");
        }
        return $dates_in_range;
    }