if (startTime.isAfter(endTime)) { setNextDay(true); } else { setNextDay(nextDay); }
setNextDay(nextDay);
    public TimeInterval(TimeOfDay startTime, TimeOfDay endTime, Boolean nextDay) {        setStartTime(startTime);        setEndTime(endTime);        // this.setNextDay(nextDay);        // never trust the data from the user :D        if (startTime.isAfter(endTime)) {            setNextDay(true);        } else {            setNextDay(nextDay);        }    }