Anybody that knows me knows I am obsessed with clocks and timers. So naturally I am going to tell you when there is a major bug that could upset how accurate your clocks are.
In 2005 a new law was passed that changed the start of Daylight Savings Time from the first Sunday in April to the second Sunday in March, in the US. This is 3 weeks earlier than it used to be. Canada will be following the US and will also be changing the date as well.
Software created before this law was passed has the potential for screwing up. And computers aren't the only devices that can be affected by this...your old VCR or wrist watch has the potential of having problems too. Any device that contains a clock that adjusts for Daylight Savings Time can be affected.
Some older operating systems that are affected (Windows 95, 98, ME, 2K) are not longer supported and there is no patch available to correct it (if you know of a good 3rd party one, leave the link in a comment). For these operating systems, you will have to turn off the automatic time adjustment and fix it manually when the change is supposed to occur.
For those running XP, there will be a patch available that will be sent out as an automatic update on Tuesday. You will need to have Service Pack 2 in order to receive this update.
Vista users are immune, as that operating system was created after 2005 and doesn't have this bug.
You can still be affected by this bug even if your operating system is patched, corrected, immune....other people may not have fixed theirs. Be very careful about trusting times for meetings and appointments from March 11 to April 1...confirm them and make sure everyone's clocks are synchronized, otherwise there could be problems with people showing up at the wrong time.
Also, avoid any type of transactions where the date is important within an hour of midnight, unless you know the system that will be recording the transaction is corrected. This means that your transactions could be recorded with the wrong date if you are not careful. Don't put off paying your car insurance till the last moment or you could find yourself with a lapsed policy.
Also be aware that any software that you use to update the time on your PC automatically, will need to be patched. Please check with the company that released that software for a patch or newer version. Most of these programs check with an official time server that gives the time in GMT and the software just subtracts time based on the date. If the date used in the software is wrong, your clock will be wrong.