During 2005, the US Congress passed the Energy Policy Act of 2005. Among other changes, this act modifies the start dates and the end dates for daylight saving time (DST). This is likely to be a source of confusion for many since new DST period is now four weeks longer than it used to be (in the US). Unless you apply some updates, it is possible that the time zone settings for your computer's 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.
To help you to resolve potential issues in your environment, MS has published some tools and associated KB articles:
- The Daylight Savings Time Help and Support Centre. With help about how to update your computer.
- KB 930879 describes how to address the issue using the Exchange Calendar Update Tool.
- MS has also created an interesting VM-based tool described in and available from a download from Microsoft.com.
- For a step by step guide, see this entry in the Exchange team blog.
My advice: unless you do business totally outside the US, consider taking a look at the issue, and start updating your system(s).