The selection element does not always show the correct range in MVVM scenarios, in which the view model validates the range. The problem is only present in WPF.

When SelectionEnd is equal to PeriodEnd, and PeriodEnd is at midnight (00:00:00), then selection title shows incorrect selection end.

To reproduce consider the following xaml:
    <telerik:RadTimeBar PeriodStart="1-Jan-2010 12:00:00 AM" 
                        PeriodEnd="31-Dec-2011 00:00:00 AM"
                        
                        SelectionStart="1-Jan-2010 12:00:00 AM" 
                        SelectionEnd="31-Dec-2011 00:00:00 AM"
                        
                        SelectionTitleFormatString="{}{0} - {1}"
                        />

PeriodEnd == SelectionEnd == 31-Dec-2011 00:00:00 AM, but title is: "01/01/2010 00:00:00 - 30/12/2011 23:59:59"

As in our app we display date with "dd MMM yyyy" format, the displayed selection end differs by one day from the real one, which is a serious issue.