public function ajaxProcessProductRoomsBookingDetailsOnMonthChange()
 {
     $month = Tools::getValue('month');
     $year = Tools::getValue('year');
     $query_date = $year . '-' . $month . '-04';
     $start_date = date('Y-m-01', strtotime($query_date));
     // hard-coded '01' for first day
     $last_day_this_month = date('Y-m-t', strtotime($query_date));
     $hotel_id = Tools::getValue('id_hotel');
     $room_type = Tools::getValue('id_product');
     $adult = Tools::getValue('num_adults');
     $children = Tools::getValue('num_children');
     $num_rooms = 1;
     $obj_booking_dtl = new HotelBookingDetail();
     while ($start_date <= $last_day_this_month) {
         $cal_date_from = $start_date;
         $cal_date_to = date('Y-m-d', strtotime($cal_date_from) + 86400);
         $booking_calendar_data[$cal_date_from] = $obj_booking_dtl->getBookingData($cal_date_from, $cal_date_to, $hotel_id, $room_type, $adult, $children, $num_rooms, 1);
         $start_date = date('Y-m-d', strtotime($start_date) + 86400);
     }
     if ($booking_calendar_data) {
         die(Tools::jsonEncode($booking_calendar_data));
     } else {
         die(0);
     }
 }