Here's the code I have on the aspx page.
<telerik:RadDatePicker id="dtReviewPeriodEnd" ImagesPath="/css/telerik/Calendar/" style="vertical-align:top;" Runat="server" EnableEmbeddedSkins="false" SharedCalendarID="sharedCalendar" Width="80px" DateInput-ReadOnly="true" />
<telerik:RadCalendar ID="sharedCalendar" runat="server" EnableMultiSelect="false" RangeMinDate="2006/01/01" Width="180px" Height="180px"></telerik:RadCalendar>
Does this help?