docs: def as_iso8601(self, include_millis=False):
          """
          example: 2016-08-13T00:38:05.210+01:00
          """
          date = self.__datetime.strftime("%Y-%m-%d")
          time = self.__datetime.strftime("%H:%M:%S")
  
          # millis...
          if include_millis:
              micros = float(self.__datetime.strftime("%f"))
              millis = ".%03d" % (micros // 1000)
  
          else:
              millis = ""
  
          # time zone...
          zone = self.__datetime.strftime("%z")
  
          # Z format...
          if float(zone[1:]) == 0.0:
              return "%sT%s%sZ" % (date, time, millis)
  
          # numeric format...
          zone_hours = zone[:3]
          zone_mins = zone[3:]
  
          return "%sT%s%s%s:%s" % (date, time, millis, zone_hours, zone_mins)