Today John O'Conner blogged on Sun's new tzupdater tool which allows existing JRE installs of version 1.4 or later to be modified to reflect timezone changes. Recently JRE updates were released to account for Australian and United States timezone changes. From the readme:
The tzupdater tool is provided to allow the updating of installed JDK/JRE images with more recent timezone data in order to accomodate the U.S. 2007 daylight saving time changes (US2007DST) originating with the U.S. Energy Policy Act of 2005. While Sun recommends utilizing the latest Sun Java SE JDK/JRE update release as the preferred vehicle for delivering both timezone data updates and other product improvements such as security fixes; if the end-user or system-administrator is unable to use the latest Sun JDK/JRE update release, this tool provides a route of updating timezone data while leaving other system configuration and dependencies unchanged. The 1.0 version delivers Olson data tz2006n which has also been included in the following Sun Java SE JDK/JRE releases: 6, 5.0_11, 1.4.2_14, 1.3.1_20.