We tested date selection when creating news items and it works fine with us, both on TIU sample site and on a new site.
Do you mean the date selection with the TIU sample home page, where some of the dates are selected (3, 8, 10, 11, 15, 20 )? All other dates are disabled as there are no events associated with them.
Please let us know if you meant something different and give us details so we can reproduce the problem locally.
the Telerik team