docs: def _get_string_slice(self, key):
          """Adapted from pandas.tseries.index.DatetimeIndex._get_string_slice"""
          parsed, resolution = _parse_iso8601_with_reso(self.date_type, key)
          try:
              loc = self._partial_date_slice(resolution, parsed)
          except KeyError:
              raise KeyError(key)
          return loc