Sun provided a Timezone Updater tool to patch Java with the new timezone data. The Java Timezone Updater is a jar file that you need to run from the command prompt with a series of command options. You need to run the Java Timezone Updater for each and every JRE available on the client machine! A typical client machine will have four to five different versions of the JRE.
We had people at the client’s site try to update our client machines with the Timezone Updater, but the bug still keep popping up. We then thought of fixing this in code with some sort of conditional chunk of code but that is just trying to fix a bad bug caused by a bad policy decision with a bad software hack because of a bad JRE update. Since our desktop client runs on Java Web Start, we thought that the best solution was to have our Web Start client run only on a newer version of the JRE that already has the correct and current timezone data. This is not entirely the most accommodating solution for the end user because each client machine now needs to have the correct JRE installed or else our application will not start.
Read the complete post : http://www.juixe.com/techknow/index.php/2007/07/25/daylight-standard-time-fiasco-with-java