code: def _parse_time(self, tokens):
          
          return self.time_parser.parse(self.parse_keyword(Keyword.WHERE, tokens))
docs: Parse the date range for the query
  
          E.g. WHERE time > now() - 48h AND time < now() - 24h
          would result in DateRange(datetime_start, datetime_end)
          where
          datetime_start would be parsed from now() - 48h
          and
          datetime_end would be parsed from now() - 24h
  
          :param tokens:
          :return: