docs: def parse_and_normalize_url_date(date_str):
      """Parse a ISO 8601 date-time with optional timezone.
  
      - Return as datetime with timezone adjusted to UTC.
      - Return naive date-time set to UTC.
  
      """
      if date_str is None:
          return None
      try:
          return d1_common.date_time.dt_from_iso8601_str(date_str)
      except d1_common.date_time.iso8601.ParseError as e:
          raise d1_common.types.exceptions.InvalidRequest(
              0,
              'Invalid date format for URL parameter. date="{}" error="{}"'.format(
                  date_str, str(e)
              ),
          )