Having a similar issue… Client computers run a localized version of Windows XP Professional (PT-BR). Time offset between clients and server is -3 hours. Server is set to America/Sao_Paulo (GMT -2 due to DST). Both Server and Clients are set to same Windows TZ (clocks are in sync)
Searched the net and found a page with a Java applet which displays the current timezone being used by JVM. Opening the site from inside clients shows timezone as “America/Rio_Branco”, which is indeed GMT-5. I created “Spark.vmoptions” and tried a couple of possibilities like America/Sao_Paulo, GMT-3:00 and Brazil/East, but Spark still showed the 3 hour difference in message timestamps.
I even tried replacing the JVM zi file (replacing Rio_Branco with Sao_Paulo). That corrected the time in the web clock java applet, but not on Spark (wasn’t it supposed to get the time from the JVM?). Then I decided to re-read the post pertaining to this issue and find out that I had missed something… the Spark.vmoptions does not work with .MSI installs (that’s what I was using). Reinstalled using the .EXE package and now it’s working!