public void ChangeDayInSchedule(int id, int newdayid)
 {
     ScheduleDaysList.Find(item => item.ScheduleDayId == id).days = Days.GetDayById(newdayid);
 }
        public ScheduleDays CreateScheduleDay(int id, int scheduleid, int dayid)
        {
            ScheduleDays scheduleday = new ScheduleDays(id, Schedule.GetScheduleById(scheduleid), Days.GetDayById(dayid));

            ScheduleDaysList.Add(scheduleday);
            return(scheduleday);
        }