private double nightPortion(double angle) {
       double calc = 0;

	if (adjustHighLats == AngleBased)
		calc = (angle)/60.0;
	else if (adjustHighLats == MidNight)
		calc = 0.5;
	else if (adjustHighLats == OneSeventh)
		calc = 0.14286;

	return calc;
    }