Yesterday, October 28th, would have been the timeframe for the US Daylight Savings Time changeover under prior rules. The new rules call for the US DST “Fall Back” to occur in the early morning of Sunday, November 4th. Here's where SharePoint stands:
WSS 3.0 and MOSS 2007 do not need a fix to work with this year's DST changes.
WSS v2 and SPS 2003 need to install the update, http://support.microsoft.com/kb/924881. The update includes an updated timezone.xml file.