You can follow suggestions in this post
to change the date time format.Another option is subscribing for ItemDataBound event of the public repeater control and there getting the data item which is IContent. From the IContent you can get the metakey - PublicationDate and parse it to the format you want.
All the best,
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!