code: def normalize_date_aggressively(date):
      
      def _strip_last_part(date):
          parts = date.split('-')
          return '-'.join(parts[:-1])
  
      fake_dates = {'0000', '9999'}
      if date in fake_dates:
          return None
      try:
          return normalize_date(date)
      except ValueError:
          if '-' not in date:
              raise
          else:
              new_date = _strip_last_part(date)
              return normalize_date_aggressively(new_date)
docs: Normalize date, stripping date parts until a valid date is obtained.