docs: def _parse_date(self, raw_value):
          "Convert raw data to datetime.date"
          nday = bytes_to_bint(raw_value) + 678882
          century = (4 * nday - 1) // 146097
          nday = 4 * nday - 1 - 146097 * century
          day = nday // 4
  
          nday = (4 * day + 3) // 1461
          day = 4 * day + 3 - 1461 * nday
          day = (day + 4) // 4
  
          month = (5 * day - 3) // 153
          day = 5 * day - 3 - 153 * month
          day = (day + 5) // 5
          year = 100 * century + nday
          if month < 10:
              month += 3
          else:
              month -= 9
              year += 1
          return year, month, day