code: def set_range(self, start=None, end=None, occurrences=None):
          
          if start is None:
              if self.__start_date is None:
                  self.__start_date = dt.date.today()
          else:
              self.start_date = start
  
          if end:
              self.end_date = end
          elif occurrences:
              self.__occurrences = occurrences
          self._track_changes()
docs: Set the range of recurrence
  
          :param date start: Start date of repetition
          :param date end: End date of repetition
          :param int occurrences: no of occurrences