Microsoft released recently the October 2011 cumulative DST update for Exchange Server 2003 SP2.
“This cumulative DST update implements time zone changes in several time zones. These time zones are listed in this article. This cumulative update also addresses DST changes that were updated in previous cumulative updates. We recommend that you install the latest DST updates for your operating system.
For more information about an update for DST changes in several countries, click the following article number to view the article in the Microsoft Knowledge Base:
2570791 (http://support.microsoft.com/kb/2570791) August 2011 cumulative time zone update for Windows operating systems
For more information about the effects of DST changes on other Microsoft products, visit the following Microsoft website:
General information about the effects of DST changes on other Microsoft products (http://support.microsoft.com/gp/cp_dst)
For more information about how to configure DST for Windows operating systems, click the following article number to view the article in the Microsoft Knowledge Base:
914387 (http://support.microsoft.com/kb/914387) How to configure daylight saving time for Windows operating systems”