code: def get_end_time(self):
          
          mda_dict = self.filehandle.attributes()
          core_mda = mda_dict['coremetadata']
          end_time_str = self.parse_metadata_string(core_mda)
          self._end_time = datetime.strptime(end_time_str, "%Y-%m-%dT%H:%M:%SZ")
docs: Get observation end time from file metadata.