I am afraid RadCalendar does not support the desired functionality. However I will forward it to our developers so they consider implementing it in future versions of the control.
I also need to mention that you can use the keyboard arrows and mouse wheel in the DateInput of the RadDatePicker to change the selected date. For that purpose, set in the InrementSetting of the DateInput the InterceptArrowKeys and InterceptMouseWheel properties to true.
I hope this helps.
the Telerik team