Your questions: It’s time to “Fall Back” again in North America. What’s the point of DST?

Late tonight in much of North America, people will turn their clocks back an hour as Daylight Saving Time ends in 2018.

Today on Twitter, I saw a great question from Ken, quoting the Seattle Times reprinted article by Frank Kummer on the point of Daylight Saving Time:

IMHO, it’s all about the economics and politics.

Mr. Kummer notes that 84 percent of European citizens were in favor of doing away with it, but that there’s no similar movement in the U.S. Well, maybe not today at the Federal level. Actually there’s plenty of activity at the State level in the States: over the last couple of years we’ve spoken with many different representatives who’ve proposed or opined on making moves for a number of different reasons.

Generally, politicians propose legislation that generally follow one of two model proposals with different supporting facts: 1) to move their state to perpetual daylight saving time, or 2) to move to permanent standard time (effectively abolishing DST). (…)

States like Florida, Mississippi and New Mexico considered the former, while Alaska, Oregon, South Dakota, Texas, Utah and Washington looked at permanent standard time. On the worldwide stage, we often see similar considerations from countries and sovereign states, to perpetually embrace or abandon DST, often hitting the news this time of year for early in the spring. Some of these efforts had reasonably long lead times. Back in 2011, I wrote on the @Microsoft corporate blog about the end of daylight saving time in the Russian Federation. (…)

But like the immortal title of the famed Thunderball sequel “Never Say Never Again”, the government considered a return to seasonal or perpetual Winter Time a year later, depending upon whom you were speaking at the time. But I digress. In the States, this was last addressed at the Federal level in 2005 with the amendments to Energy Policy Act of 1992. Specifically, the changes were to the start and daylight saving time to amend the Uniform Time Act of 1966. (IIRC, some of our own folks even participated in the discussions and submissions.)

In supporting such amendments to what would become the Energy Policy Act of 2005, you can understand why lobbyists for this change would include the Foundation to @FightBlindness. But you also saw the National Association of Convenience Stores support the changes (think a lighter Halloween) joined by the Sporting Goods Manufacturers Association. (Couple those with the lobbyists from oil and gas supporting other provisions of the Act)

You can learn more in this piece by NPR, which is covered in Michael Downing’s book “Spring Forward: The Annual Madness of Daylight Saving Time.” (…)

So it seems that like much of the legislation we see in state and national politics, such moves to change DST are driven by business interests rather than health and goodwill. In 2006 when working on the effort in Windows and across Microsoft, I heard how candy manufacturers had long lobbied their desire to see the Halloween holiday be included in the summertime Daylight Saving Time change. Imagine: if kids were able to spend more time trick-or-treating, home bound chocolate and candy corn benefactors would need even greater stores of candy. (And this all to the often repeated call of “Halloween Apples” in my hometown, tho’ we rarely received any.)

Lobbyists against the changes in 2005 included the National PTA, and of course the Calendaring and Scheduling Consortium and the Air Transport Association. Remember a time when Airlines used to print those small voluminous books of the schedules for departure and arrival times for all their flights?

Now please pardon me while I take a break to refresh my memory and make a fresh cup of ☕️ to mull on a few topics particularly around the areas where different studies supported or detracted DST.

It’s all coming back to me, like the time we watched closely back in late 2007 as Venezuela moved to a newly created time zone, shifting by 30 minutes to -4:30h UTC (…)

For some changes, the notification comes challenging late, as we saw with Morocco and Pakistan in 2008, switching from one traditionally used GMT offset to a new one. Such changes impact customers and partners in the regions who use local time zones, as well as others entities engaged in business in or with the region. (Remember those flight guides?)

Unfortunately, due to the short notice provided for these late breaking changes with short runways, companies can’t always provide updates incorporating these changes. So when Morocco admirably decoded recently to stop the “fall back” (at least in the northern hemisphere) to Daylight Saving Time, it was only decided and announced days before the country was scheduled to turn clocks back. It may save “an hour of natural light” () but it creates a maelstrom of activity around the world as people speculate on whether or not the changes will be locked perpetually. (…)

That’s why Microsoft created and published a policy in response to Daylight Saving Time and Time Zone changes around the world. (…) It includes some simple recommendations to provide, first, ample advance notice (12 months or more) before a change to DST or alignment with a particular time zone,

Second, an official confirmation of the changes, and third, a yeoman’s effort to promote the change – locally and on the worldwide stage (as often such changes have far-reaching implications). So as more and more states and countries consider such changes, these guidelines become increasingly important. (…)

In my day job, we still have regular discussions on the topic as a group of resident “time lords” keep time and our systems on track. (…) (Although I’d like to think of myself more in line with the sharp wit and sarcasm of the Fourth incarnation of the Doctor, I’m more in line with the Third)

Having worked across all of our product groups (originally the majority was on-premises products) for the last few years on things like DST, it‘s fitting that much of my time is now spent on how we retire many of those same products in our corporate-wide end of support efforts. We dedicated several cycles with our online services to the topic of time and date management, and you see that reflected in the increased attention to the topic across the company. So, back to the initial question: What exactly is the point of daylight saving time? The not so easy answer: It depends. The initial benefits often touted more daylight hours during the day when more people were active, provide greater energy savings, lower incidents of crime, heart attacks and crime. (Mom and apple pie sentiments)

Increasingly, it seems to gain legislative momentum when specific commercial interests see material benefits as a result of making a change.

The @PBS @NewsHour said it well, capturing the absurdity of how “opponents and supporters of daylight saving are still not sure exactly what it does.“ (…)

And how, a century after Congress first passed the inaugural daylight saving legislation in the States, are there still questions and debates as to why DST is still a thing. Without planning, it will continue to be challenge to track future changes in a timely fashion.




Implications of Proposed Changes to Daylight Saving Time in the United States

This past week, I’ve contacted and spoken with several legislators on the plethora of proposed changes to use of daylight saving time around the States. I even had a call from my friend, Rich Kaplan, the new CEO over at the Microsoft Alumni Network, reminiscing over a few of these recent moves. The efforts fall under two main proposals: to move their state to perpetual daylight saving time, as is the case in Florida, Mississippi (died in committee) and New Mexico*; or, to move to permanent standard time, as proposed in Alaska, Oregon, South Dakota, Texas, Utah** and Washington. (I recently heard that the bill to adopt daylight saving time in Arizona has been held up by the House leadership, effectively dead in committee.) I’m not sure what will happen in Florida and New Mexico, given that the United Sates Code (15 U.S.C. §6(IX)(260-7)) stipulates that states shall either implement the semiannual daylight saving time changes or remain on standard time throughout the year.

Asked what I worry about this now, I recalled Winston Churchill’s quote:

“Let our advance worrying become advance thinking and planning.”

I appreciate that the legislators in several states have thoughtfully called for such changes to take effect in 2017 or later (2021, in Oregon). But a few, like Texas and Washington, would have the changes as early as fall of 2015. Without adequate time to react, such changes can be challenging for individuals to manage and for companies to support. Not a very united effort in the States as a whole.

That’s why Microsoft has recommended (via the tab “Microsoft Policy in Response to DST/TZ Requests” in the left nav of the page) that governments take at least one year from the time the proposals are enacted into law for the change to occur. As an example, I look to the timeline provided in the Energy Policy Act of 2005, outlining sweeping changes to daylight saving time in the United States, that allowed for nearly a year and a half before the change was implemented.

But just as important as the time needed to implement these changes, also consider the technical implications of moving to permanent daylight saving time rather than moving solely to standard time.

imageAs noted in my last post, a few states have proposed to move to year-round standard time and drop daylight saving altogether, a fairly straight forward approach. Given that many devices (PCs, phones, tablets and services) allow you to select whether or not products use a daylight saving time offset, shifting the device between daylight saving and standard time twice a year is fairly simple, and turning off the automated change is quite simple. In Windows, you may check the option for the device to “Automatically adjust clock for Daylight Saving Time” if your time zone observes daylight saving time and you want your computer’s clock to be adjusted automatically when daylight saving time changes. (In the States, that’s on March 8, 2015.)

But moving to permanent daylight saving time may not be easily implemented on devices that are no longer supported and don’t receive updated rules: this includes computers, mobile phones, embedded devices, connected systems and services. For instance, older operating systems that are out of support (such as the venerable Windows XP) no longer receive updates which include the updated set of worldwide time zones and daylight saving offsets.

More information than you’ll care to remember is available in KB 914387, How to configure daylight saving time for Microsoft Windows operating systems.


* – an added twist: New Mexico, today in the Mountain time zone, would move in the current proposed legislation to the central time zone and be known as “mountain daylight savings time.”

** – Feb 9, 2015: Latest reports indicate Senate Resolution 1 died in committee.


Also available via


Oregon may repeal daylight saving time… in 2021

Regular readers of this blog and familiar with the efforts Microsoft has put forward in working with many in the industry to achieve more seamless transitions on new DST, time zone and related policies. Recently, I read Oregon Senator Kim Thatcher’s proposed bill (SB99) would repeal daylight saving time in the state. At a time when other states have similarly proposed changes to their time zone and observance of DST (a couple of notable examples include a proposal in Utah to drop daylight saving time and one in New Mexico to observe daylight saving time throughout the year) this one from Sen. Thatcher is quite refreshing:

The Oregon law would not take effect until January of 2021. Plenty of time to get the word out on the change.

A change in a state’s time zone and observance of DST would have national and worldwide impacts on time references for interstate and international commerce. Each year there are many changes to daylight saving time and shifts in time zones around the world, some of which are late-breaking. Without adequate time to react, such changes can be challenging for individuals to manage and for companies to support. (You may recall when Venezuela erratically and abruptly moved to a new time zone shifting to -4:30h UTC.)

There are a few key things we recommend is for governments to provide…

  1. Ample advance notice (1 year or more) of the planned change, from the time it is enacted into law to the time of the change (as provided in the Energy Policy Act of 2005),
  2. Official, published confirmation of planned changes to DST or time zones on governmental websites and in official publications, and
  3. Concentrated promotional efforts communicating the change to affected residents and citizens.

Even better, Sen. Thatcher stipulated that this proposal would be put to a vote “of the people for their approval or rejection at the next regular general election held throughout this state.”

Brava, Senator. Brava.

Also available at


Available now: December 2014 cumulative time zone update for Windows operating systems

Is it December already? That means that holiday treat we know at the December cumulative time zone update for Windows operating systems is out, available as kb 3013410. As noted, this update replaces the previous August 2014 CU 2981580 and includes all the time zone and daylight saving time changes released as hotfixes since then, including the monumental changes we saw in Russia in October. (ICYMI, Se my post from September.)

The following changes were made since the previous Windows cumulative time zone update:

  • Russia time zones: Russia announced that it would change its existing time zones on October 26, 2014. This change included seven updated time zones, three new time zones, and two existing time zones that merged into one.       (     
  • Fiji Standard Time: Fiji announced that the country’s new daylight saving time (DST) schedule would start on November 2, 2014 and end on January 18, 2015. The previous DST start date in Windows for the Fiji time zone was October 26.(     
  • Cape Verde Standard Time: We have changed the name of the “Cape Verde Standard Time” time zone to “Cabo Verde Standard Time.” The display name for this time zone is now “(GMT-01:00) Cabo Verde Islands.”

So what should you do to make sure that your computers are ready for the change?

Most applications and services reference the underlying Windows operating system for their date and time related rules, with some exceptions. We outline the various software updates to select Microsoft products (including various releases of the Microsoft Windows operating systems, Microsoft Office and other applications) on the Microsoft Daylight Saving Time Help and Support Center. There, we have information and links to updates for various products in mainstream and extended support affected by this change, as well as other various changes to DST offsets and time zones around the world.

If you use Microsoft Update on your PC at home, chances are you’re already covered. The latest update from October may already be installed on your PC if you have turned on Automatic Update in Windows. This ensures you’ll get the latest security and other important updates from Microsoft automatically. If you’re not sure if the update has been applied, visit the Microsoft Update site for more information.

If someone manages your network at work, it’s likely the needed updates are schedule to be deployed to your computers and devices, if they haven’t been installed already.

For IT professionals managing PCs, servers and Microsoft software installations, please visit for more details. Also, visit the support websites of any other software companies to see if you need to apply any updates. It’s not just Microsoft software that may require updates. Additionally, for the latest change in Russia, we provided specific details and guidance at

While Microsoft’s Services infrastructure will be updated to reflect DST changes, it’s important that your computers — both clients and servers that interact with these services — also have the latest Windows cumulative updates for DST and time zone changes applied in order to ensure data integrity.

As always, thanks to the good folks in Windows and those across the company working to help manage time… particularly the number of daylight saving time and time zone changes that come in from various corners of the world. You can find this and much more documented over at and over on the Windows blog at



Windows Updates for New Russia Time Zones Now Available

As I highlighted last month, the Windows team in OSG have supported the new Russian time zone changes. What with the changes to the Ruble symbol and now the eleven new time zones and move away from daylight saving time, perhaps I should rename my blog…

As noted, the target release date was September 23, 2014, which was met: the Russian Federation time zone update is available now at: and on the Microsoft Russia site at

Please note that if you’re using any of the current Russian time zones or doing business with customers or partners in the affected territory, the guidance we received from the Russian government that the change will occur on October 26, 2014 at 2:00 am local time. When we see time zone offset changes (due to daylight saving time) and time zone revisions, the time change is often executed with the next click of the clock after 1:59:59h. (Well, not always: Samoa made its historic move at 23:59:59.)

Consumers and Small/Medium Business customers should ensure that Windows Update is turned on if you don’t have someone managing your computer. The update packages for all currently supported Windows platforms are available via Windows Update. If someone manages your network at work, it’s likely the needed updates are schedule to be deployed to your computers and devices, if they haven’t been installed already.

If you live or work in some of the regions affected by this change, you may want to check the time zone setting on your device (available in the Settings on Windows 8). In some cases in the affected areas, your device may be set to a new time zone. Some other applications may require changes or adjustments to the time and date information. In some cases, all the necessary changes automatically and you will need to take individual decisions in specific cases. For information on updating software from other vendors, please visit their Web sites.

For more information, please visit – details will be added to the site on other products and services as available.