private static DateTime getXDay(int year, int month, DayOfWeek weekday, byte count) => TimeFunctions.GetXWeekDay(year, month, weekday, count) ?? new DateTime(year, month, 1);
private static DateTime getLastDay(int year, int month, DayOfWeek weekday) => TimeFunctions.GetLastWeekDay(year, month, weekday);
private static DateTime adminProfDay(int year) => TimeFunctions.GetLastWeekDay(year, 4, DayOfWeek.Saturday).GetPreviousWeekDay(DayOfWeek.Wednesday);