code: def _try_assign_utc_time(self, raw_time, time_base):
          
  
          # Check if the raw time is encoded UTC since y2k or just uptime
          if raw_time != IOTileEvent.InvalidRawTime and (raw_time & (1 << 31)):
              y2k_offset = self.raw_time ^ (1 << 31)
              return self._Y2KReference + datetime.timedelta(seconds=y2k_offset)
  
          if time_base is not None:
              return time_base + datetime.timedelta(seconds=raw_time)
  
          return None
docs: Try to assign a UTC time to this reading.