Daylight Saving Computer Challenges

Charles Babington
Washington Post Staff Writer
Monday, March 5, 2007; 12:00 PM

Getting e-mails from your office IT department about upgrading your work computer because Daylight Saving Time is happening early this year? If so, you're not alone. Just as computer experts were worried about computers coming to a halt during Y2K, the early time change may be disrupting electronics, too.

Washington Post staff writer Charles Babington was online Monday, March 5 at Noon ET to discuss how Daylight Saving Time is affecting your computer or handheld device.

The transcript follows.

Read more here:

Countdown to Confusion (Post, March 2)

Clocks' Early Spring Forward May Bring About a Few Falls (Post, Feb. 1)


Charles Babington: Hello, thanks for joining the chat. As all of you know by now, Daylight Saving time will start three weeks early this year (and end one week later). It is the first change in 20 years, so many computer programs will need to be updated to "spring forward" and "fall back" on the correct days. Let's discuss.


Keymar, Md.: I use the calendar provided by MS Outlook 2003. Starting on the 11th until the "normal" time of DST all my appointments are 1 hour late and the "all Day" appointments are two days long, going from 1 am to 1 am. How can I fix this?

Charles Babington: I see several such questions in my queue. Microsoft seems to be making a serious effort to answer these concerns. Their website, which has a lot of information, is

I hope this helps.


Rockville, Md.: No problems for any of the MAC computers in our house. There are three laptops, and three desktops of various flavors. The automatic updates from Apple keeps all these systems up to date. The only problem is to change our wrist watches! It takes me a while as my watch (and computers) are on 24 hour digital display. It takes a bit of time to ratchet through 23 hours. Our cars will also need changing. The mantle clock is not a problem as we have none.

Charles Babington: Not surprisingly, I see several thumbs-up messages from happy Mac owners.... As for the clocks on car radios: They can be really tricky, can't they? Sometimes the Volume up and down buttons change the hours (or minutes). Sometimes it's the Channel up and down buttons. My advice: Figure it out while you are parked, not driving. Please.


Columbia, Md.: Get a Mac!

Charles Babington: Like I said....


Bowie: Wouldn't it have been better to begin a new DST schedule in the Fall, rather than the Spring? Almost every April, I encounter someone late for something on DST-Sunday. Wouldn't it make sense to have the people with computer problem be an hour early for something in November?

Charles Babington: When Congress voted in mid-2005 to make the change (effective in 2007), I guess lawmakers didn't see it that way. They felt there was more daylight to be "saved" in the early spring. My prediction: People are going to feel it's awfully dark (and perhaps cold) on the first few mornings after the switch. Only now are we getting a little peek of sunlight at 6:30 a.m., and none whatsoever at 5:30. A week from today, that dark dark hour will be 6:30, and the bare glimmer of light will be 7:30. Won't it feel like we've been pushed back into winter?


I use the calendar provided by MS Outlook 2003.: Charles, I use Act and it's quite alright. MS is just too quirky about things, this included.

Charles Babington: Thanks for writing.


Holland, Mich.: My O.S. is Microsoft XP, do you know if Microsoft will send a fix, for daylight saving time? Thanks, Robert

Charles Babington: If you go to the Microsoft site, noted above, they walk you through all types of operating systems, including XP. Good luck.


Reston, Va.: How could the industry be caught with their pants down like this? I work for a very large "online" company in "America" and had to patch almost 1000 systems in the past few weeks. Patches are STILL being released by HP; I'm expecting one on March 7 to fix some mistakes made by a previous version from early February. This is turning out to be much more impacting than Y2K...

Charles Babington: This is an interesting comment from Reston, and it generally runs counter to the comments I heard last week from various industry officials when I was researching the story. They told me they think the DST issue will be much less worrisome than Y2K (at least the potential that Y2K had) because, generally speaking, the worst that can happen with a DST foulup is that people will be late for meetings, etc., by one hour. Do others out there share Reston's view?


Anonymous: Do I really have to change my computer's time clock? why not wait a couple of weeks and it will correct itself?

Charles Babington: Sounds reasonable to me. Actually, you don't have to wait a couple of weeks. The switch to DST should occur at 2 a.m. on Sunday the 11th. I suppose you can stay up late Saturday night and watch the computer... Or sleep in (c'mon, it's Sunday!) and check when you wake up.


Chantilly, Va.: Charles, My 3 pcs have the updates which include the patch. Automatic download. Good to go.

Charles Babington: Rock on.


Kingstowne, Va.: One of my cars has a built-in GPS navigation system. The time normally updates automatically from the satellite. But what should happen this week? Does a GPS unit rely on the longitude to determine time zone, then compute the difference from GMT (in which case I'll have to fix it myself), or does it read the actual correct local time?

Charles Babington: A very good question, and I don't know the answer. Any help out there? When it comes to cell phones, they automatically update the correct time based on the closest cell tower. In other words, if you are on the east coast and you start driving west, your phone's clock will automatically switch from Eastern time to Central time as soon as your signal is "handed off" to a cell in the Central time zone. But it's not always easy. Arizona, for instance, still doesn't observe Daylight Saving time, but the large Navajo reservation in Ariz. does.. What's a cell tower to do? Anyway, I don't know how GPS handles this problem.


Washington, D.C.: Watches and car clocks are not an issue; it's the same amount of effort as it would have been if the DST dates were left alone. It's the automated assistance our computers give us so we do not need to manually make the change. Nobody ever expected the rules to change.

Charles Babington: Well, I'm not sure you can say "nobody" expected the rules to change. Daylight saving has a long and rather serpentine history. It was tried briefly during WWI, then dropped. It was resurrected years later, and the start-and-stop dates often changed. Only the last 20 years have seen a long period of stability.

Chat quiz: According to historians, who was the first prominent American to suggest daylight saving time? (Hint: he was trying to save candle-power, not electric lights).


Arlington, Va.: Is the situation really that different for Macs and Windows PCs? It sounds like Windows PCs are automatically covered except for older systems. Is Mac automatically updating even its older systems (OS 9, etc.)?

Charles Babington: Like Microsoft, Apple has an extensive talker/tutorial for its Mac computers. Find it at:


Baltimore, Md.: Well, it isn't a computer issue, it's a sunrise issue that makes me mad. For the past month, I have dealt with traffic jams during my morning commute because at 7:30AM the sun is shining right in everyone's face, too low for the car's sun visor to block it, so everyone slows down. Now I have to re-live that month all over again.

Charles Babington: I'm afraid so, Baltimore. Keep those windshields as clean as possible, that will help reduce the glare. Good luck.


Fairfax Station: The article and potential impacts mentioned seem relatively benign for the desktops and at least in the US there seems to be plenty of publicity about the change. What worries me is the possibility of impacts on the logic controller side such as building maintenance systems, automated system that control items based on sunrise, sunset etc., but especially the internationally interfaces such as airline schedule, trains, other transportation, financial market timings, trade events etc.

I don't think Congress gave this much thought about the overall impact and costs besides oil? Do you see significant disruptions potential?

Charles Babington: When we spoke with representatives of major industries such as the airlines and banks, they said their IT people were on top of the situation and there should be no significant problems. I guess we'll know for sure on the mornings of the 11th, 12th and 13th.


Battle Creek, Mich.: Answer to chat question - Ben Franklin

Charles Babington: Correct! Go to the front of the class, Battle Creek.


Indianapolis, Ind.: No, the worst that can happen is not being late for meetings. I work in a very large hospital and have patched so many computers. XP, UNIX, 95, 98. This is costing hospitals a mint because these clocks have to be right on tests and treatments. Plus being litigious as we are. Also Indiana just switched to DST last year so everything is new to us. it's not as simple as just changing a clock.

Charles Babington: Thanks for writing, and welcome to DST after a long holdout, Indiana.


sun is shining right in everyone's face, too low for the car's sun visor to block it, so everyone slows down. Now I have to re-live that month all over again.: Charles, Tell the poster and other commuters to buy a good pair of sun glasses and keep them in the car. Sun visors do little to decrease the glare of a rising sun.

Charles Babington: I respectfully must disagree. I'm a huge fan of good sunglasses. But when the sun is really low and you're driving, a well-placed visor is the best remedy by far.


Battle Creek, Mich.: I would say there are actually 4 dates we'll have to be concerned with - the two new spring/fall dates for time change, and the original spring/fall dates that were originally planned for. Has there been much recognition that there are 4 days for problems?

Charles Babington: I've heard no discussion of possible problems on the "old" dates for switching to and from DST. In other words, we might suffer from a "spring spring" scenario?


Salem, Ore.: There was a bit on the Today Show this morning about the possible trouble in the health care industry, as many medication dispensing machines in hospitals and care facilities could give incorrect doses by running too long, double dosing, etc. at changeover time.

Charles Babington: I saw that segment, and Indianapolis expressed similar concerns. Let's hope the IT people at all hospitals, clinics, nursing homes, etc., have been on top of the situation.


Southern California: Were astronomers consulted about the DST change scheduling? I assume that sunup and sundown times are symmetric around the solstices. By that reasoning, if DST ends in early November, about 7 weeks before Dec. 21, the winter solstice, then shouldn't DST begin 7 weeks after Dec. 21, or in mid February?

Charles Babington: Hmmm, something tells me that senators and House members did not consult astronomers (well, perhaps about their reelection prospects, but not about this). Perhaps an informed staffer from the Hill can prove me wrong.


Columbus, Ohio: OUTLOOK appointment problems. I just checked It only provides the download. It does not address the messed up times for appointments in OUTLOOK. Does anyone have any suggestions? Thanks.

Charles Babington: Any thoughts for Columbus?


Pete from Arlington: I'm not sure I understand the fuss. If Microsoft's sending a update patch for 98 percent of all PC's and all handheld wireless devices getting a signal from a cell tower will get their DST time stamp from the tower automatically, all that's left is my appliance clocks and other timepieces. I have to do those manually anyway. What am I missing?

Charles Babington: Let's hope you're not missing anything, Pete, and that all of this will seem like a teapot tempest come the middle of next week.


McLean, Va.: I run Linux and my system had the issue handled through an automatic update. Since all the software runs off of the system time, it all updates automatically. If Linux (well, Red Hat Linux) handles it that easily, why wouldn't Windows?

Charles Babington: Thanks for the update on the Linux update.


Reston Again: Anything time-based, like security, logins, databases, etc will be impacted. If time is off on a system by just a few minutes, authentication schemes that require a time stamp to match from client and server will fail and you are locked out. If one system goes from 01:59 to 03:00 and another from 01:59 to 02:00, they will not be able to communicate and passwords will have to be recovered through sometimes very painful methods. All my colleagues (not Industry reps or leaders, but the real systems Administrators in the trenches) feel that the impact will be far far greater than Y2K and some messed up calendar appointments.

Charles Babington: Interesting. For society's sake, let's hope your colleagues are wrong. We should know for sure in one week.


Tucson, Ariz.: My state does not participate in daylight savings time. Are watches, computers etc. set to default to changing to DST?

Charles Babington: Well, we're all responsible for our own watches, right? As for Arizona: I don't know how the computers will be handled. Have you checked the main MS and Apple sites?


OUTLOOK appointment problems.: Charles, Tell the poster to go buy Act. Too much Microsoft is not a good thing.

Charles Babington: Another happy consumer.


Great Falls, Va.: Isn't it time for a global shift to universal (GMT) time? Wouldn't that solve a lot of problems - everyone would know when it is 0800, and the local variances for opening of business, meal times, etc. would be no harder to learn than whether the country/state changed to DST on 11 March, not at all, etc.

Charles Babington: So, those of us on the U.S. east coast would get off work around midnight GMT? And wake up noonish? I can't see it flying.


Fort Worth, Tex.: Has Microsoft pushed any repair patches during their fix-it Tuesday patch pushes in the past couple of weeks? And if so, how can one tell if they have received the patch? Thanks, Darryl

Charles Babington: I hope the tutorial on the MS site will answer your question, Darryl.


Washington, D.C.: My DVD player takes the date and time from the cable system. Should I assume that this will make the DVD player adjust for the change automatically? I don't plan to record anything on the night of March 10/11.

Charles Babington: I would assume the cable feed would take care of the update.


Charles Babington: Thanks for the good questions and comments. Good look to everyone springing forward at 2 a.m. on Sunday!


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