If you haven't already read the e-mail from Neil Davin or visited the Time Zone Update pages at the Help Desk site, I would suggest starting there for a little background on what is happening. If you want a little more information on the Daylight Savings Time (DST) changes, I will try to oblidge with a little Q&A:
[ CAUTION: Some of the information in this post, or linked to, will be quite technical in nature. Consider yourself warned! ]
Where can I get more information?
The best place to start is at Microsoft's Daylight Saving Time Help and Support Center.
Do I need to update my Mac?
Yes, but you probably already have. Installing the Mac OS X 10.4.6 Update "Makes Mac OS X aware of United States Daylight Savings Time (DST) changes enacted by the Energy Policy Act of 2005." Source: http://docs.info.apple.com/article.html?artnum=303411. For Entourage users, you also need to install the Microsoft Office 2004 for Mac 11.3.3 Update. This is available at http://www.microsoft.com/mac/.
What needs to be updated in Windows to accommodate the new DST rules?
Windows computers store a complete time zone database in the Windows registry. The information for the current time zone gets copied into the "current control set" when you change time zones. Manually updating a windows computer requires updating the registry, and then forcing that information to be copied into the current control set. This is basically what the Windows Updates are doing. They are also adding some "dynamic time zone information" that they say will be used to help with any future changes.
What Windows versions are effected?
Windows Vista does not need to be updated; it already has the new time zone information. Windows XP and Windows Server 2003 can be updated by running patches released by Microsoft. These will be pushed out to all Emerson computers through the Automatic Update process. Windows 2000 computers (and earlier versions) will not have a patch released and must be updated manually. For Windows 2000 computers at Emerson, we will be pushing out the update using Group Policy. For non-Emerson computers, they can be updated manually using a tool called tzedit.exe, which is available from Microsoft. Complete instructions are available at: http://support.microsoft.com/kb/914387
For Windows Mobile see: http://support.microsoft.com/kb/923953
Windows CE devices see: http://support.microsoft.com/kb/923027
Why is my Outlook calendar all messed up? or
Where can I get more info about the Time Zone Update Tool for Outlook?
Microsoft offers a lot of information in the Knowledge Base article covering the Update Tool: http://support.microsoft.com/kb/931667/en-us. I recommend reading the section titled Different scenarios in Outlook.
What other software is effected?
Right now, the only other software we know of that will need a significant upgrade is ColdFusion. You can read Adobe's TechNote for more details.
What about Public Folder calendars?
Public folder calendars are just like any other outlook calendar--they will need to have events created under the old DST rules updated so they appear accurate when viewed with the new rules. You can update them manually, or you can actually use the Time Zone Update Tool. On the main screen for the tool, click the "Custom..." button next to where your mailbox is selected. From there you should be able to select Public Folders, and navigate through to find your calendar.
Where can I find out how to update my smart phone?
If you have a Verizon Wireless phone, see http://www.verizonwireless.com/dst. For Cingular/AT&T, see http://www.cingular.com/support/knowledgeBase.do?content=KB77065.html. And for T-Mobile, see http://support.t-mobile.com/knowbase/root/public/tm23412.htm.