I was forwarded some email that said the dates for Daylight Saving Time are
changing, and that I need to take steps to make sure that my computer’s clock
would be set correctly. The links went to the Microsoft web site, but I
couldn’t figure out what I need to do, if anything.
What do I need to do?
Daylight Saving Time (DST) in the United States will be extended by four
weeks, beginning this year. It’ll start three weeks earlier and end one week later
than it would have by the old rules.
So the question boils down to: how will your computer find out about the new
As is so often the case … it depends.
Become a Patron of Ask Leo! and go ad-free!
The good news is that for many of you, nothing is required.
If you’re already running Windows Vista, you’re done. Vista already
incorporates the necessary change. Nothing to see here.
If you’re running Windows XP SP2, and you have Automatic Updates
turned on (as I feel you should), you’re done. Your copy of Windows either has
been, or will be, updated in time for the new DST rules.
If you’re running SP2 but don’t have Automatic Updates enabled, then visit
Windows Update sometime before March
11, 2007 to manually pick up the DST update.
If you’re running Windows XP without SP2, you need to first install SP2 (as
I feel you should), by visiting Windows
Update. After the SP2 install, continue with subsequent updates, and you’ll
get the DST update as part of the bargain.
If you’re running versions of Windows older than XP with SP2 … Microsoft appears to
provide no help. Personally, I’d visit Windows Update anyway, particularly if you’re running Windows
2000. Support for Windows 9x is certainly over, but Windows 2000 still has a
large corporate installed base, and it wouldn’t surprise me if a fix were made
Automatic Updates turned on (as I feel you should), you’re done.”
For those older versions, or if you elect not to take the available
update(s), you’ll need to do things manually, twice a year. You should first
turn off “Automatically adjust clock for daylight saving changes” and then
update your clock by hand on the second Sunday in March and on the first Sunday
Microsoft Office is also affected by this change. (You should first update
If you’re running Office 2007, you’re done. Office 2007 is already up to
date with respect to this change.
If you’re running older versions of Office, and if you use the
calendar or reminders features of Microsoft Outlook, Microsoft has provided a
Time Zone Data Update Tool for
Microsoft Office Outlook.
Most operating systems are affected one way or another, so if you’re not
running Windows, you’ll want to check with your OS vendor. For example Apple’s
Mac OS X included updates for this issue in their 10.4.5 update. Other OS’s that
include an automatic update feature will typically also have handled this
Applications are more difficult to predict. Most will rely on the operating
system to handle everything and will not be affected. Others, like Microsoft
Office Outlook which have special calendaring and related features may
be impacted and may need to be updated. Check with the specific application
vendor if you’re not sure.
Keep an eye out.
I would pay particular attention to your computer’s clock on the following
March 11, 2007 – the new start of DST. Your clock
should “spring forward” one hour on this day. If you’ve applied the appropriate
patches and have automatic adjustment enabled, it should do so
April 1, 2007 – the old start of DST. Your clock
should not change on this day. If you failed to update, it might.
October 28, 2007 – the old end of DST. Your clock
should not change on this day.
November 4, 2007 – the new end of DST. Your clock
should “fall back” one our on this day.
And naturally, keep an eye on your other programs, particularly calendaring
and scheduling applications to make sure that they’re all following the new
rules as well.