Microsoft has set up a page to assist users with checking their Vista and XP system to make sure they are in compliance with all the local Daylight Saving Time (DST) rules. In some cases, time zone settings may be incorrect, according to Microsoft. There are no known issues with Mac OS X.
The Microsoft advisory says: "Observance of DST, and iSummer Timei in much of Europe, is often different around the world; many areas, countries and territories shift their clocks at different times throughout the year. During these changes, clocks are usually shifted by one hour. Some locations follow a set of standard, uniform rules for the start and end dates of DST, but some locations determine the dates on a much more dynamic basis.
"Unless certain updates are applied to your computer, the time zone settings for your computeris system clock may be incorrect during this four-week period. In particular, you must make sure that both your Windows operating system and your calendar programs are updated."
Microsoft is still working out how to implement calendars in their OS, according to Information Week on Friday: "Thousands of Microsoft Exchange Server 2007 users found that out the hard way last week when the software got flummoxed by the February 29 leap day."
There are no known issues with Mac OS X in the U.S. Recently some countries have been tweaking their DST rules, and updates have frequently appeared for MaBaSoftis World Clock Deluxe as a result, so worldwide Mac OS X customers may still want to check their Software Updates.
Apple customers can read more at the Apple Support Page on Daylight Saving Time.
For most of the U.S., Daylight Saving Time goes into effect Sunday Morning, March 9th at 2:00 AM when clocks are turned forward one hour.