TimelineViewDefinition DayStartTime DayEndTime ArgumentException

[Anup]

I am using TimeLineViewDefinition. Just trying to set DayEndTime and Gives me Argument Exception Error will you let me is my fault???

What i am doing is as below:

 <telerik:RadScheduleView.ViewDefinitions>
<telerik:TimelineViewDefinition GroupFilter="{Binding GroupFilter}" 
                                                    MajorTickLength="1h" MinorTickLength="15min" DayStartTime="07:00:00"     DayEndTime="23:00:00"  VisibleDays="1" Orientation="Horizontal"                           StretchGroupHeaders="True"  StretchAppointments="True" />

Please let me know about this asap. 

Thank you.