Ant Drewery

There has been a lot of discussion recently about the changes to daylight savings time in the USA. The changes have come about due to the 2005 Energy Policy Act. In previous years, DST in most of the USA ran from the first Sunday in April until the last Sunday in October. From 2007 DST will be from the second Sunday in March to the first Sunday in November. I’m based in the UK so these changes do not affect me directly but I work for a global company with a global Windows/Exchange environment so there is an impact to address.

Microsoft has had a patch available to address the issue since late November 2006. This has recently been updated to include DST changes in other time zones around the world. My recommendation is to deploy this patch to ALL Windows machines in your environment. The patch can be distributed via WSUS if you have this facility available.

Once the patch has been deployed you may need to correct entries in the Outlook calendar. Microsoft have provided two tools to do this. The first (http://support.microsoft.com/kb/931667/) is a tool that needs to be run individually for the affected users. The tool requires user interaction so you may want to distribute a link to a file share along with detailed instructions on how to run it and it’s potential impact. You should also give examples of why the tool is necessary so that the users have a good understanding.

The second tool is for Microsoft Exchange (http://support.microsoft.com/kb/930879) and will allow you to update the calendars centrally. If you are going to take this approach you need to carefully consider the risks of a blanket update. KB930879 lists the pros and cons of this method.

You can find more information from Microsoft about the DST changes here: http://support.microsoft.com/gp/cp_dst

UPDATE:

There are now patches for Blackberry (http://www.blackberry.com/select/dst2007/index.shtml) and Windows Mobile (http://www.microsoft.com/windowsmobile/daylightsaving/default.mspx).

I was working on a Small Business Server 2003 system at the weekend. My first job of the day was to install the latest security patches then reboot. Unfortunately after the reboot the server had dropped off the network and the IPSec Services service had failed to start. Manually trying to start it resulted in "The system cannot find the file specified". I tried another reboot for good measure but got the same result. I then disabled the service and rebooted. The server stayed on the network but components like Sharepoint and OWA would not work.

My initial suspicion was that this was caused by one of the security patches I had applied so I uninstalled them one at a time trying to find which was the culprit. However, after they all had been removed the issue still persisted. A bit of Googling the event logs showed that the IPSec Services were entering "block mode" and led me to the solution to my problem with this article:
http://support.microsoft.com/?kbid=912023. It seems that there was a corrupted file in the policy store. After resolving the issue I reapplied the security patches without any trouble.