Daylight Saving Time (DST 2007) Starts 3 weeks earlier in 2007

Since 1986, we have gotten used to “springing forward” on the 1st Sunday in April and “fall back” on the last Sunday in October.  But last year – 2006 -- marks the end of it and starting this year – 2007 – we will be “springing forward” 3 weeks earlier.   For 2007, the day we lose an hour of sleep falls on March 11th.  But for IT professionals, there might be more hours of sleep lost due to the patches and user support needed to accommodate this change.  Let’s take a look at what are the patches needed. 

The effects of the change are especially important to Outlook users and Exchange administrators because of how appointments and timestamps are going to be affected.   For administrators of outdated Windows operating systems and applications, that effect is even more profound. 

How various versions of operating systems are affected:

How various versions of Exchange are affected:

Recommended order of applying DST patches for your Outlook/Exchange environment

After referring to the charts above on whether the versions of your servers and applications are supported, it’s now time to apply the patches.  This is also the recommended order of patching that they communicate to their partners.  If appointments are created between patches are applied, time skew could happen.  Applying these patches closely together will minimize that possibility.

Note:   If your organization has users who create many recurring calendar items using Outlook Web Access, your patch sequence will differ slightly.  Refer to KB931667 for details.

1. Apply server2003 operating system patch from KB931836 “February 2007 cumulative time zone update for Microsoft Windows operating systems” onto your servers, or here is the patch for 32-bit Windows Server 2003.

2. Apply XP operating system patch onto your client machines from the same article KB931836, or here is the patch for XP 32-bit machines.

3.  Apply update to Windows mobile devices if you have them in your environment, refer to Microsoft’s  Daylight Saving Time 2007 Update page from the Windows Mobile team.  There are multiple ways of applying the patches, whether you or your users connect to a PC to synchronize or synchronize “over the air”.  

4. Apply the Exchange 2003 CDO patch outlined in KB926666 “Update for daylight saving time changes in 2007 for Exchange 2003 Service Pack 2”.  This will ensure that Outlook Web Access will also be patched properly.  Here is the direct link to the patch for both Standard and Enterprise editions.

5. Run either the Exchange or Outlook Time Zone Data Update Tool to update Outlook calendars that are saved on the Exchange servers based on KB931667.  So what is the difference between these two tools?  See the next section.

6. After everything is done, double check all your appointments in the following range.  If the appointment times are 1 hour late, the update did not execute perfectly.  You can correct it by manually changing the appointment time as well.

1. March 11, 2007 and April 1, 2007

2. October 28, 2007 and November 4, 2007

 

Difference between the Exchange tool and the Outlook tool

A key point to note is that both tools are not patches.  They’re created to help you automate the appointment time change process.  However, as with any automation, certain things could still slip through the crack.  Double checking by a human is always preferred. 

If you choose not to run the tool, you can simply check the individual appointment items and adjust the time accordingly.  If you have a meeting and you are the meeting requestor, by resending the meeting request after adjustment of the meeting time, your recipients/attendees will be sent the update notice. 

The Exchange Time Zone Data Update Tool (Exchange tool) is basically a wrapper around the Time Zone Data Update Tool for Microsoft® Office Outlook® (Outlook Tool).  The Exchange tool just handles the processing on the server side and the Outlook tool does it on the client side.  Any updates that can be done by the Exchange tool can be done by the Outlook tool.  So if you’re running the IT operation for your organization, the Exchange tool may be more useful.  In some situations, you may need to deploy both tools and that will not have any adverse effect. 

What if I don’t do anything at all?

If you do not apply any patch at all, during the time windows of March 11, 2007 -- April 1, 2007 and October 28, 2007 -- November 4, 2007, your clock will be off by an hour.  If you do not have any timestamp-sensitive operations, you may get by. 

However, it is important that you do not simply adjust the computer clock by an hour to mimic the time change.  Your computer’s local time is shown based on the UTC time +/- time zone different +/- DST 2007 adjustment for those time periods.  Adjusting the computer clock actually changes the UTC time which will cause more problems.