public void UpdateEvent(int startHour, int startMinute, int endHour, int endMinute)
 {
     if (type == WORK)
     {
         StartTime = new Time(startHour, startMinute);
         EndTime   = new Time(endHour, endMinute);
         DatabaseManager.UpdateEvent(this);
     }
     Console.WriteLine("ERROR: called CalendarEvent.UpdateEvent on non-WORK type event.");
 }