The Tacos library project provides components and ajax behaviour for the Tapestry java web application framework. Most of the functionality is based on the exceptional dojo javascript library. Thanks dojo!

It's intent is to provide a library of high quality components that may be used in your tapestry application, as well as provide a core infrastructure for using ajax related logic in these and your own components and pages.

Nice javascript library that could be helpful.  It has a widget for date and time...