}
public boolean isBusinessDay(Date date) {
Weekday w = date.getWeekday();
int d = date.getDayOfMonth();
Month m = date.getMonthEnum();
int y = date.getYear();
// equinox calculation : TODO: is double usage the right type ???
final double exact_vernal_equinox_time = 20.69115;
final double exact_autumnal_equinox_time = 23.09;
final double diff_per_year = 0.242194;