private void AddSelection()
{
if (HoverEnd != null && HoverStart != null)
{
foreach (DateTime item in SelectedDates)
{
RemovedItems.Add(item);
}
SelectedDates.ClearInternal();
// In keyboard selection, we are sure that the collection does
// not include any blackout days
SelectedDates.AddRange(HoverStart.Value, HoverEnd.Value);
}
}