code: public boolean setTimezone(TimeZone zone) throws CommandExecutionException {
          if (zone == null) throw new CommandExecutionException(CommandExecutionException.Error.INVALID_PARAMETERS);
          JSONArray tz = new JSONArray();
          tz.put(zone.getID());
          return sendOk("set_timezone", tz);
      }
docs: Set the vacuums timezone
  @param zone The new timezone to set.
  @return True if the command has been received successfully.
  @throws CommandExecutionException When there has been a error during the communication or the response was invalid.