code: def _calculate_timestamps(self):
          
          self._timestamps_data = []
          if not self._is_reversed:
              self._calc_timestamps(self.st_time, self.end_time)
          else:
              self._calc_timestamps(self.st_time, DateTime.from_hoy(8759))
              self._calc_timestamps(DateTime.from_hoy(0), self.end_time)
docs: Return a list of Ladybug DateTime in this analysis period.