private void FillQuarters() { // generating a list of quarters descending from current date DateTime quarter = DateTime.Now.Date; while (quarter > new DateTime(1995, 1, 1)) { quarter = dateFunctions.PreviousQuarter(quarter); quarters.Add(quarter.Date); } Quarters = CollectionViewSource.GetDefaultView(quarters); Quarters.CurrentChanged += Quarters_CurrentChanged; Quarters.MoveCurrentToFirst(); }