Some of you may have missed the following Alert Bulletin posted by Sun Microsystems yesterday.  It deals with the change in DST and "Olson time zone data tzdata2005r or greater incompatibility". According to the information available from Sun regarding this alert sunsolve.sun.com/search/document.do there is a problem with Eastern, Hawaii and Mountain Time Zones and Sun Java 2 software.

It appears that there are 2 issues that affect the ability for the software to calculate correctly.  Both of the issues are covered by bug reports from Sun.

Sun bug 6466476

This issue is an incompatibility in the definition of time zone objects identified by the time zone IDs "EST", "MST" or "HST". Prior to Olson data 2005r these 3 IDs refer to zones which observe daylight savings time. For Olson data 2005r or later these 3 IDs refer to zones which do not observe daylight savings time.

bugs.sun.com/bugdatabase/view_bug.do

Sun bug 6530336

It effects the parsing of date strings containing the strings "EDT", "HDT" or "MDT", for example "July 4th 2007, 1:00 pm EDT".

bugs.sun.com/bugdatabase/view_bug.do

Thanks to Colm for providing the information.