In 2005, the US Congress passed a bill changing the start and end dates of Daylight Savings Time (DST). Starting this year, DST begins three weeks earlier and ends one week later than previously. This change affects virtually every electronic device and computer program that deals with the time of day.

If you use Windows, Windows Mobile, Outlook, Microsoft Exchange, or pretty much any other electronic anything, you are affected too.

Exactly what this means to you depends on what gear you have and how you use it. We're going to focus on Microsoft products here, but don't be surprised if your digital clocks or Tivo are also confused by this. If you don't use your gear to keep track of your schedule (or as an expensive digital clock like I do sometimes) this isn't a real big deal. The time on your gear will be off by an hour for a while, but nothing is going to blow up.

If you use things like Microsoft Outlook, Exchange, or SharePoint in your work, you do need to care. Even getting a reminder to pop up at the right time requires all these programs to agree on what time it is.

Imagine the chaos of scheduling a meeting when all your gear is updated for the DST change properly, but one attendee has updated Windows and not Outlook, and another has updated all their desktop stuff but forgot about their Windows Mobile smartphone where they keep a copy of their schedule and...

...the net result of this is that unless you and everyone you work with get all your gear updated properly, there's going to be lots of scheduling confusion around the office during the expanded weeks of Daylight Savings Time.

Making fixes for Microsoft products
Microsoft has done a great job of making information and tools available for updating their products. They have created patches, or updated programs, or detailed instructions on how to fix the issue on each of your Microsoft products.

Unfortunately, fixing this can be complex.

For example, users of Windows XP with Service Pack 2 can already download an update that makes Windows handle the change. But users of earlier versions of Windows don't get that update, and will have to make changes manually.

For organizations that use Windows and Exchange and Outlook, the order in which they make the updates matters too, as does the speed with which they make them (imagine the unpredictable results of someone trying to schedule a meeting while all this updating is in progress).

Contributing Editor Bill Mann is a freelance technology writer/instructor who has trained over 2000 people in the use of Microsoft Outlook. Check out his book, "How to Do Everything with Microsoft Office Outlook 2007" on Amazon.com. For more on Outlook, visit his website at http://www.living-with-outlook.com. You can also write him at Outlook2007@techforyou.com.