code: def _format_strings(self):
          
  
          values = self.values
  
          if not isinstance(values, DatetimeIndex):
              values = DatetimeIndex(values)
  
          if self.formatter is not None and callable(self.formatter):
              return [self.formatter(x) for x in values]
  
          fmt_values = format_array_from_datetime(
              values.asi8.ravel(),
              format=_get_format_datetime64_from_values(values,
                                                        self.date_format),
              na_rep=self.nat_rep).reshape(values.shape)
          return fmt_values.tolist()
docs: we by definition have DO NOT have a TZ