Watching the Clocks

Setting VCR clocks automatically created a lot more problems than anyone realized

13 min read

In October, IEEE Spectrum reported on two problems confronting some U.S. users of videocassette recorders having automatically setting clocks ["Does anybody really know what time it is?," by Tekla S. Perry, October, pp. 26-28]. In some places they were seriously fast and in others seriously slow. The so-called autoclocks get their information from a digital time stamp sent by most Public Broadcasting System (PBS) stations during the television screen's vertical blanking interval. Sometimes called the XDS (extended data service) signal, for a time it was also being sent out by some Fox network affiliates. A VCR with an autoclock searches for the time signal, starting with the lowest-frequency channel in its vicinity and moving higher. Once it finds the signal, it stops searching

In San Jose, Calif., for example, some viewers were faced with clocks that were 24 minutes fast, because the time stamp being sent by a local PBS affiliate was incorrect. In other parts of the country, some viewers were faced with clocks one, two, or three hours slow, because some Fox affiliates were passing along time stamps set to the local time in Los Angeles. These errors were fixed last summer.

Following the publication of the article, Spectrum expected to hear from a few readers who experienced these problems, and we did. Some of them also described rather creative solutions for fixing their clocks. What surprised us more in the flood of e-mail that arrived was the number of localized problems that still exist. In fact, it seems, to date, VCR autoclocks cannot be fully trusted.

Now for the letters:

Fast by 24 minutes

Yes, my VCR was affected by the 24-minute bug. It did not occur to me to care whether it was my autoclock or PBS. My solution was to override the autoclock. I did that for quite a time. Then I became annoyed at having to reset the clock at the start and conclusion of Daylight Savings Time (technology can make one lazy!), so I returned it to the autoclock mode and it has been working OK since. [Because Kuzminski was affected by the San Jose problem, by the time she returned to autoclock mode, the signal, unbeknownst to her, had been fixed. --Ed.]

Roxy Kuzminski


Is it just me?

Wow! I thought I was the lone person seeing this time error and looking for a reason and/or resolution.

I was in Alexandria, Va., and took time to visit PBS to discuss the problem with them. Their position was to blame either the local affiliate in Atlanta or my cable operator. So I called the chief engineer at the Atlanta PBS station. He denied all knowledge of the problem. His view was that they had no local control of the signal and passed along what was sent over the network. He would, however, look into it and get back to me. He never did.

So I turned my attention to Comcast, my cable operator. It did not know (or seem to care) about this problem and said it only passed on what was delivered to them by the broadcaster.

My solution was to disable the automatic time-setting feature on the VCR. It seems to do a reasonable job of time-keeping without any external assistance. I have now taken on the task of checking the clock monthly and correcting it as necessary.

Thanks to David L. Wilson [the San Jose Mercury reporter who first wrote about the clock signal] for hanging on to a story and not taking "I don't know" for an answer. And thanks to [Spectrum's Tekla] Perry for compiling the information and getting it into the hands of many of us who find this timing discrepancy annoying at the very least.

Barry Kanne


The jet-lagged signal

It was a great and interesting story. I noticed that when my VCR with an auto clock went through the default setup the clock was one hour ahead. I then got into the JVC manual [for the VCR] and learned how the time stamp was part of the PBS signal and how to manually set the VCR to the local PBS affiliate. Once the VCR was properly pointed to PBS, the time has been dead on. Our local Fox affiliate in Austin, Texas, is Channel 7 and PBS is Channel 18.

Rick Erickson

I, too, was affected by the XDS VCR auto-clock issue during the past year. I bought a new VCR in spring 2000 and was excited that it would autoset the time. After setting it up for my time zone (Eastern) and telling it that we observe daylight savings time, I turned it loose. Pretty soon it was two hours fast. I corrected it manually several times only to discover later that it was two hours fast again. My time signal comes in over Channel 6 on cable, which is the WB affiliate in Boston (TV 56). I eventually gave up and turned off the auto-clock feature. I considered returning the VCR to the point of purchase.

Then, in August, I had the idea to attempt to fool the thing. I set the time zone to Mountain Time, two hours behind local, and re-enabled auto-clock.

Behold, the autoset time was now correct. Don't ask me why it took so long to think of this...

Of course, two weeks or so later the problem with the XDS transmission was finally corrected and my VCR reverted to being two hours fast again. I shrugged my shoulders and reset the time zone back to Eastern, and all was well again.

When I read your article, I finally realized what had happened. I still check the time on the VCR for accuracy every night before I go to bed, however.

Michael J. Starks


Other troubles surface

I thought I was going nuts! When I purchased my Sony VCR about six months ago I decided to try the autoset mode. Mind you, I am perfectly capable of setting the time myself--even without the instruction manual.

Up until about a month ago the autoset time was correct compared to NIST [the National Institute of Science and Technology, which broadcasts standard time signals]. Around August or September, however, I noticed that it was consistently running a minute fast. I put the VCR back into the manual mode so that I could display the correct time. Having read Perry's article I decided to go back to the autoset mode to see if the error was still there. Sure enough, PBS time still showed a minute fast compared to NIST. So now it is back to the manual set mode for me.

H. Robert Schroeder, Trenton, N.J.


Starting just last week [in September], our VCR clock has generally been off. It is currently two hours ahead, but it has been two hours behind (I thought maybe Chicago time) and three hours ahead (Hawaii time?). I had been waiting for it to be corrected, but was about ready to report it to the cable company.

Sid Bertram, San Luis Obispo, Calif.


I live in Los Angeles and noticed that my VCR clock on my JVC was off an hour. I tried taking the VCR off auto mode, but it drifted, so I changed time zones and watched the clock every day. JVC claims they check the time at midnight or so. This worked for a few days, and then I noticed that the time changed to a reset to my time zone.

I had never had trouble setting the clock on VCRs before, but with the new so-called automatic setting I have a hell of a time. My new Panasonic has this feature, and it wants to do it only its way and not as I intuitively think it should work.

Howard Helman


My VCR would mysteriously reset its time to be off by one hour. The explanation given in the Perry article does not explain my problem. I live in San Diego, which is in the same time zone as Los Angeles. So if I were receiving XDS clock signals from a Fox affiliate (XETV or KTTV), then I should not have noticed any problem.

I generally used my local PBS station for the XDS clock signals (KPBS), but in frustration I would resort to using KCET (Los Angeles) instead. My VCR makes this process difficult and does not indicate which station it is using for the XDS clock signal. It would usually end up using KPBS again anyway.

In February I wrote to my local PBS station (KPBS) and mentioned the VCR clock setting being off by an hour occasionally. I received a reply confirming that they were aware of the XDS clock signals being off. They also mentioned that they had just installed a new computer to control the clock system. I have not seen any further problems with the VCR clock.

Jay Foster


I live near Jackson, Michigan. My autoclock is still one hour slow. My cable company is AT&T Broadband (formerly Summit Leoni). AT&T Broadband has two Fox channels (Lansing [7] and Detroit [3]) on their system with channel numbers lower than the lowest PBS channel (Lansing [13]).

Please pass the word to AT&T and Fox to get their act together.

Richard Hensel


I have a related problem with the local XDS-equipped stations. My TV clock seems to change time occasionally by several hours (the minutes are off, too) and will stay that way for a day or two and then mysteriously reset back to normal.

I suspect programming that is taped at the station for broadcast later is not having the XDS signal stripped before going to the transmitter. Our market has two stations with XDS, both PBS affiliates, so the possibility exists that either station is the cause.

Russ Kinner, Holland, Ohio


When I first set up my girlfriend's VCR, the autoclock set the time one hour fast. Her VCR has a set-up option that allows you to turn off the autoclock setting feature, so I turned it off. The clock was great when I manually set the time.

As an experiment, I turned the autoset back on, and again the clock was set one hour fast. I figured out from that that the problem was in the time signal that was being broadcast, and that's about as far as I took it.

We are in the Kansas City metro area. The VCR will indicate that it has found a channel with the XDS time signal, but does not indicate which one it is, so I do not know who is providing the signal it is setting to.

Marty Morse


Although I did not see the problem that the author described, every time that Daylight Savings starts and stops, my VCR does not catch up for as much as two weeks. My solution has been to disable the automatic time update until my local station, WTTW Chicago, catches up. I was going to call them, but I figured I would have more clout if my subscription was paid, which it wasn't at the time.

I will watch how it goes at the October time change. I did not have the Fox problem, as they broadcast on Channel 32 here, and the two PBS stations are at 11 and 20.

John Haller


It won't just go away

The source of the problem is the broadcasters/cable sources, and unless they are made aware of the problem and take the steps to fix it, it will not go away. It should be obvious that the accuracy of the time is only as good as the setting on the equipment that inserts it. The real problem is that the engineers using the equipment were never properly instructed how to set the time and check that it remained correct. And it is not always so obvious what equipment inserts the time.

Not just the PBS channels are inserting, and they may not even know they are doing it. My problem was caused by the Disney Channel. It was putting out the West Coast time in the East Coast feed, so my VCR was setting its clock three hours off.

I spoke with an engineer at the transmission site for the Disney Channel. After some investigation he found the time signal inside the packet of information inserted by the newly installed equipment for the V-chip system, which screens TV programs for content inappropriate for children. So he set that clock and the problem was fixed. I soon found, however, that attending to that clock is not part of regular procedures, because when Daylight Savings Time began the clock was not changed. So I had to call the engineer and remind him to change it. I am waiting to see what will happen at the end of October when Daylight Savings Time ends.

This problem goes beyond the Disney Channel. I recently let my VCR set itself from the Starz Channel, and the clock was one hour off. Someone needs to better instruct them (and other channels) about this clock signal and how to maintain it. The automatic clock setting feature of VCRs is a helpful technology, but, as these events show, it only works if all participants are trained in the part they must play. Equipment manufacturers must be sure they clearly identify to the broadcasters/cable operators what signals they insert into the video and what must be done to be sure the information is correct.

Stephen A. Martucci


Christmas joy affected

I got a new GoVideo VCR last Christmas. Usually when it first turns on, it claims that it is searching the channels for the PBS station to set the time. But then it finishes, and the time is not set. It keeps displaying -:--. About two days later the time will magically get set, usually two hours off. Then a day later the time will magically get set closer to the right time, only it is always off by about two to five minutes. This is annoying because I miss the beginning or end of programs I tape. So I have just gotten used to going into the menu and choosing to set the clock manually.

I did not report it to GoVideo because I assumed it was a problem of the channel sending the signal. I did not complain to PBS because it was never really clearly documented that PBS was sending the signal. Since it was only two to five minutes off, I assumed it was a problem of someone setting the clock to a slightly different time.

Ashley Wise


When a VCR was not enough

I had to laugh when I read your story about self-setting clocks in new VCRs. Earlier this year I bought both a new VCR and TV. Both contain self-setting clocks. Little did I realize that I had started upon a futile adventure.

The VCR immediately searched for, found a clock signal, and set its clock to within a couple of minutes of the correct time. The TV on the other hand required that I enter the channel on which it would find the clock signal. After entering the PBS station channel number, the TV set its clock close to the correct time, but not the same time that the VCR was set to.

The situation went down hill rapidly from there. Both clocks continued to disagree about the correct time, with the added twist that they would suddenly reset their time to be anywhere from one to three hours off from the almost correct time. In other words, the VCR might be an hour fast and the TV two hours slow.

I then had several interesting discussions with my cable provider (Cox cable). First, it told me that the self-setting clock signal was not broadcast in my area. After I explained why I found this statement to be untrue, though fascinating, Cox did some further checking. Its final answer was that the local PBS station did not broadcast the self-setting clock signal and it did not know what signal I was getting. With help like that, you know you are on your own.

My solution was to program my VCR clock manually. But if there exists a way to override the autoclock feature and manually set the time displayed by the TV, I have not found it. No matter how many times I reset the TV clock, it is only a matter of time before it reverts to jumping about in hour increments.

Joe Jones


Delayed reaction

I have had a clock setting on my JVC VCR running five minutes fast. Your article answered a lot of questions about the possible reasons. My machine allows for an override of the clock setting, and that has been my solution. Once I have manually reset, it does not appear to slip out of correct time for several weeks, but eventually it seems to do so.

Chuck Wakeman


Self-correcting, sort of

I had a autoclock problem with a two-year-old Panasonic VCR. After a power failure during a thunderstorm, the VCR couldn't find the autoclock clock signals. My cable system delivers PBS from Channel 12 in Philadelphia, Channel 39 in the Lehigh Valley, and NJN PBS in New Jersey to the VCR. An e-mail to Channel 12 (WHYY) got a prompt reply, that something must be wrong with the VCR. It needed to be reset. I tried to do what the manual said, and it didn't work.

After about two days, the VCR autoclock started to work part of the time. It gave me one time set using the local Fox station. A few days later, it worked all the time on Channel 12.

I noted that rather than being off (early) by one or two minutes over the past two years, it was about 2 seconds later than the Boulder NIST signal.

Bill Visher


I gather from your article on PBS XDS clocks, that once the rack-mounted unit is launched, it is free to drift off on its own, fast or slow, indefinitely.

Perhaps that is why the time from WTTW, PBS 11, in Chicago, is now two minutes and 40 seconds fast.

Earl Poulson


One for Sherlock Holmes

My Super-VHS Mitsubishi HSU-70 VCR purchased 12 years ago got zapped recently, so in a rush I did a little shopping and wound up buying another top-of-the-line VCR with a zillion gee-whizzes, including "automatic time-setting of the VCR clock from a PBS broadcast signal."

That was 23 October--it was surprisingly easy to set up and I was amazed how its more sensitive tuner could get watchably, albeit poorly, the fine PBS station in Owings Mill, Md., Channel 22 broadcast. After several experiments, I declared success and shut it down at about 11:10 p.m. (in the Washington, D.C., broadcast area, which has Channels 26 and 32 nominally PBS, and Channel 5 Fox). Shutting it down triggered the self-setting clock program in the VCR ("off" doesn't mean off anymore, any more than "is'" means is, a tragedy...).

The next morning, I glanced at the self-setting clock, and it read 3:46 a.m., when every other clock (and the sun, etc.) registered 8:10 a.m.

This approximately 4.5-hour difference was eventually discussed with my VCR salesman and the tech-on-duty at Channel 26/WETA in Washington. I also called Toshiba, and learned this was not an unusual report.

My call to WETA-26 revealed:

  • They'd had a time signal failure around 6 a.m. 24 October, not at 11:10 on 23 October.
  • It was benign--just stopped, no weird numbers transmitted.
  • Although it was a "PBS program feature," there is no info or link on the PBS Web site, and PBS provides only satcom timing--local stations provide the clock value transmitted.
  • There was no common answer/guideline for this situation in PBS; maybe Fox had one, which did things from a central location.
  • The technician had no idea why my VCR would be off 4.5 hours, a number that belied the notion of "wrong time zone" or other speculation.

Upshot: I set my VCR's clock setting to manual.

John Michael Williams


Suggestions for solutions

Perry's article made me wonder: why is PBS doing this in the first place? NIST is already using our tax dollars to distribute a WWV time signal that is good to about 0.1 second. Several consumer clocks and clock radios are available that set themselves automatically and work perfectly. I have one. Why do VCR manufacturers not use that signal?

The PBS system design has all kinds of fatal flaws, some of which Perry clearly elucidated. In addition, if the XDS clocks are set manually via a computer interface, they will always include the errors of the computer clocks, which are completely arbitrary, and the serial message delay, which could be significant. As more U.S. television stations send more XDS messages, with no coordination whatsoever, more of these autoclock VCRs will exhibit random behavior.

Thomas D. Gamble, Springfield, Va.


I think PCs should also keep their clocks accurate by searching the Internet. Eventually wall clocks will do something similar.

Bruce Currivan


Central control does not work.

Another disturbing trend is the ideal of reviving centralized computers and/or data centers. We are going back to the '60s and '70s when most people used remote computers via terminals. I spent many an hour trying to figure out what went wrong when the central computer was down. Was it the modem, the terminal, the line? So did many of my colleagues. Productivity, as measured by availability of computer resources, jumped when desktops were introduced. Any individual computer failure did not affect other users significantly.

Millions of people making decisions affecting themselves do a much better job than a remotely sited individual or group. Obviously, many did not care that their VCRs showed the wrong time. Those who cared were seriously inconvenienced. I have an older VCR, without the feature. And I know how to set the clock.

If I had one of these defective VCRs, would the wrong time be imposed on it even if I had set it to the correct time? I suppose it would. Central control overrides individual control.

Al Jaszek

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