code: public static int getDayOfWeek(@NotNull final Date date) {
  		int result = getWithMondayFirst(date, Calendar.DAY_OF_WEEK);
  		return result == 1 ? 7 : result - 1;
  	}
docs: 获得日期是一周的第几天. 已改为中国习惯，1 是Monday，而不是Sundays.