/**
  * Checks whether or not the specified time is marked as available
  *
  * @param $from
  * @param $to
  * @return bool
  */
 public function isAvailable($from, $to)
 {
     return 0 < timetable_query_a($this->timetable->specifics()->where('is_available', 1), $from, $to);
 }
 /**
  * Checks whether or not the datetime is currently booked.
  *
  * @param $from
  * @param $to
  * @return bool
  */
 public function isBooked($from, $to)
 {
     return 0 < timetable_query_a($this->timetable->bookings(), $from, $to);
 }