public static void WorkdayEnd(DateTime EndTime)
        {
            //Store the ended workday in the workday history
            List <Day> lTemp = UserData.getDays();

            lTemp.Add(new Day(UserData.getWorkTimeStart(), EndTime));
            UserData.setDays(lTemp);

            //Set all workday related parameters to Zero
            UserData.setWorkTimeStart(DateTime.MinValue);
        }
        private void buttonSave_OnClick(object sender, RoutedEventArgs e)
        {
            UserData.setDays(lDay.ToList());

            Close();
        }