Exchange and Daylight Saving Time, Part 1

Since the Germans first started doing it in 1916, much of the industrialized world has adopted a system of shifting time by an hour twice per year. In Europe, this is generally known as "summer time," but in the United States and Canada it's known as daylight saving time (DST). Never shy about screwing with a perfectly workable system, the US Congress passed a law in 2005, which goes into effect this year, that changes the dates when we switch to and away from DST.

This change has many implications that the original authors of the law probably didn't think of. It's easy enough to change ordinary clocks, but many other devices keep time and will need to be either adjusted or patched by the manufacturers. For example, in my home there are two TiVos, a dozen or so computers, several wireless access points and routers, a VCR, and a PBX. All of these devices automatically adjust their clocks for DST now, but they'll need to be updated because this year DST begins earlier (March 11 instead of April 1) and ends later (November 4 versus October 28) than it has before.

The 2007 DST change poses an especially interesting circumstance for Exchange administrators. There are actually four sets of changes required:

patches for Windows, including Windows Server 2003, Windows 2000 Server, Windows XP, and Windows Mobile
patches for Exchange, which are required for OWA and other programs that use the Collaboration Data Objects (CDO) libraries
patches for Outlook, Microsoft Entourage, and other clients that create and process calendar data
updates to existing appointments that fall during the new extended DST period (March 11–April 1 and October 28–November 4)

So, what do you actually need to do? To make sure your environment is prepared for the DST changes, you need to begin by patching your Windows servers so that they'll adjust their clocks automatically at the appropriate times. The Microsoft article "2007 time zone update for Microsoft Windows operating systems" describes the process required to apply updates to Windows Server 2003 and Windows XP Service Pack 2 (SP2). Windows Vista already understands the extended DST period; Windows 2000 customers with extended support agreements will be able to get a hotfix. Users on Windows XP SP1 or Windows NT are out of luck.

Next, you should patch your client OSs. Ideally, you'd do this at the same time as the server OS patches. Don't forget your Windows Mobile clients! (I'll explain why next week.) After these patches are in place, Microsoft recommends patching Exchange Server 2003 by using the patch described in the Microsoft article "Update for daylight saving time changes in 2007 for Exchange 2003". Exchange Server 2007 already includes the patch; if you’re still on Exchange 2000 Server or Exchange Server 5.5, you can get a patch from Microsoft if you’re under an extended support contract. After Exchange is patched, the real fun starts: You have to update calendar and appointment data on your servers. That process deserves its own column, so I'll write about it next week.

In the meantime, the Web page Preparing for daylight saving time changes in 2007 is Microsoft's master reference for the whole DST update. It contains this somewhat frightening sentence in the introduction: "Please check this page at least weekly to ensure you have the latest information available." So, your homework before next week's UPDATE is to visit that page at least once!

End of Article

Nice outline and I hope people pay attention, but the reality is Microsoft knew that DST could change since the last time it was changed was in 1987 - Way before Windows NT started development! I believe it's a real pity that a world renowned company would leave something so simple and variable so difficult for administrators and companies to deal with.

I don't think people realize the impact of DST2007 yet. They will and when they become aware after showing up at appointments 1 hour early there will be a backlash.

I hope Microsoft can explain why they knew this coming since 2005 yet waited till Jan 30, 2007 to make the announcement of the required patches or no patches for those of us without an extended contract.

prehlb February 16, 2007 (Article Rating:

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Microsoft COMPLETELY dropped the ball on 2007 DST changes! They have known for 18 months this would be a headache and have done comparatively little to make it easy besides providing 24 page write-ups of excuses.

jchando February 20, 2007 (Article Rating:

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I look at is as job security. I don't believe MS dropped the ball since the law passed in after SP2 came out. Vista is ready to go and naturally so will Longhorn. It is just an update like any other and any admin worth their salt is already on this. I agree, MS could have put this out sooner, but seriously, how much earlier would you want it? At least people are talking about it.

jpgleason February 20, 2007 (Article Rating:

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Looks like there is a new manual fix for Exchange 2000:

http://support.microsoft.com/kb/930879/en-us

gnussbaum February 20, 2007 (Article Rating:

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The article http://support.microsoft.com/kb/930879/en-us indicates that it can be also used on Exchange 5.5. Is this THE solution for those who are still running 5.5?

aluke February 21, 2007 (Article Rating:

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Unfortunately kb/930879/en-us includes:
"The Exchange tool must be run on a computer that has Microsoft Office Outlook 2003 or Microsoft Office Outlook 2007 installed..."

Aetius March 05, 2007 (Article Rating:

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Does this mean the patch has to be installed on each workstation and NOT just the server?

Thanks rather annoying.

tkitch March 07, 2007 (Article Rating:

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Does this mean the patch has to be installed on each workstation and NOT just the server?

Thanks rather annoying.

tkitch March 07, 2007 (Article Rating:

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