code: @NonNull public static CalendarDay from(int year, int month, int day) {
      return new CalendarDay(year, month, day);
    }
docs: Get a new instance set to the specified day
  
  @param year new instance's year
  @param month new instance's month as defined by {@linkplain java.util.Calendar}
  @param day new instance's day of month
  @return CalendarDay set to the specified date