class PackedLocalTime {

  public static int plusHours(int hoursToAdd, int packedTime) {
    if (hoursToAdd == 0) {
      return packedTime;
    }
    int hour = PackedLocalTime.getHour(packedTime);
    int newHour = ((hoursToAdd % HOURS_PER_DAY) + hour + HOURS_PER_DAY) % HOURS_PER_DAY;
    return create(
        newHour,
        PackedLocalTime.getMinute(packedTime),
        PackedLocalTime.getSecond(packedTime),
        PackedLocalTime.getMilliseconds(packedTime));
  }

}