I just released this today, and I intend to bundle it into FullCalendar (<a href="http://arshaw.com/fullcalendar/" rel="nofollow">http://arshaw.com/fullcalendar/</a>) in the near future.
Similar but different - I wrote a lightweight js lib for parsing and formatting dates - <a href="https://github.com/zaius/jdate" rel="nofollow">https://github.com/zaius/jdate</a>