LyteByte

U.S daylight saving time is starting 3 weeks earlier than usual, on March 11, 2007. This change was authorized by the U.S Energy policy Act of 2005. But the implication of this is worst affected by the software that were created earlier to run in accordance with the old daylight saving time and yes, that includes your computer, mobiles, PDA and other electronic devices which uses a clocking software.
The software which are released recently, including Windows Vista, Office 2007 etc, seems to have corrected this. But, if you are using an earlier OS or software then you might have a wrong time for a period of about 4 weeks (3 weeks late in the spring and 1 week early in the fall), incase you fail to update.
Microsoft has warned that this could have lots of implications similar to Y2K issue. They also have listed the products which could get affected and how to determine and mitigate any serious effect. Microsoft has already released an update for Windows XP SP2 users through Automatic Update Services but in order to work you should have enabled Auto Update.
You can also do it manually by following the instructions given by Microsoft.