code: async def on_raw_333(self, message):
          
          target, channel, setter, timestamp = message.params
          if not self.in_channel(channel):
              return
  
          # No need to sync user since this is most likely outdated info.
          self.channels[channel]['topic_by'] = self._parse_user(setter)[0]
          self.channels[channel]['topic_set'] = datetime.datetime.fromtimestamp(int(timestamp))
docs: Topic setter and time on channel join.