nextHour method
Implementation
Solar nextHour(int hours) {
int h = _hour + hours;
int n = h < 0 ? -1 : 1;
int hour = h.abs();
int days = (hour / 24).floor() * n;
hour = (hour % 24) * n;
if (hour < 0) {
hour += 24;
days--;
}
Solar solar = next(days);
return Solar.fromYmdHms(solar.getYear(), solar.getMonth(), solar.getDay(), hour, solar.getMinute(), solar.getSecond());
}