                  pass
              else:
                  return parsed
  
          datetime_input_formats = '; '.join(self.input_formats)
          msg = self.error_messages['invalid'] % get_readable_date_format(datetime_input_formats)
          raise ValidationError(msg)
  
      def to_native(self, value):
          if self.output_format is not None:
 
</s> remove         time_input_formats = '; '.join(self.input_formats)
 </s> add         time_input_formats = '; '.join(self.input_formats).replace(ISO8601, 'HH:MM[:ss[.uuuuuu]]') </s> remove         date_input_formats = '; '.join(self.input_formats)
 </s> add         date_input_formats = '; '.join(self.input_formats).replace(ISO8601, 'YYYY-MM-DD') </s> remove         if self.output_format is not None:
            return value.strftime(self.output_format)
        return value.isoformat()
 </s> add         if self.output_format.lower() == ISO8601:
            return value.isoformat()
        return value.strftime(self.output_format) </s> remove                 return parsed
 </s> add                 try:
                    parsed = datetime.datetime.strptime(value, format)
                except (ValueError, TypeError):
                    pass
                else:
                    return parsed </s> remove             try:
                parsed = datetime.datetime.strptime(value, format)
            except (ValueError, TypeError):
                pass
 </s> add             if format.lower() == ISO8601:
                try:
                    parsed = parse_datetime(value)
                except (ValueError, TypeError):
                    pass
                else:
                    if parsed is not None:
                        return parsed
        datetime_input_formats = '; '.join(self.input_formats).replace(ISO8601, 'YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]')
                  pass
              else:
                  return parsed
  
        datetime_input_formats = '; '.join(self.input_formats).replace(ISO8601, 'YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]')
          msg = self.error_messages['invalid'] % get_readable_date_format(datetime_input_formats)
          raise ValidationError(msg)
  
      def to_native(self, value):
          if self.output_format is not None:
keep keep keep keep replace keep keep keep keep keep
 Add new ISO8601 setting + integration 
rest_framework/fields.py