code: def _build_time(time, kwargs):
      
      tz = kwargs.pop('tz', 'UTC')
      if time:
          if kwargs:
              raise ValueError('Cannot pass kwargs and a time')
          else:
              return ensure_utc(time, tz)
      elif not kwargs:
          raise ValueError('Must pass a time or kwargs')
      else:
          return datetime.time(**kwargs)
docs: Builds the time argument for event rules.