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Software Windows Technology IT

Meet the Guy Whose Software Keeps the World's Digital Clocks In Sync (ieee.org) 78

New submitter Wave723 quotes a story on IEEE: In many cases, the internal clock that ticks away in a laptop or desktop computer is synchronized to an official time service maintained by the U.S. National Institute of Standards and Technology (NIST). This free service shares Coordinated Universal Time with personal devices, web browsers, financial trading software and e-mail programs throughout the world. The service receives 150,000 requests per second (roughly 16 billion a day) from systems that repeatedly ask, 'What time is it?' "If you have a PC, it's probably synchronized to the time service," says Judah Levine, the man who originally built servers and programmed software to send time over the Internet for NIST back in 1993.
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Meet the Guy Whose Software Keeps the World's Digital Clocks In Sync

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  • Not from me it doesn't. I only ask maybe once a month.

    • I'm guessing they meant NTP traffic is estimated to be 150,000 requests per second, globally.
      All my machines sync to their domain controllers. The domain controllers sync to a local time server. The time server syncs to the big boy government time servers. They never see the flood of requests from my machines or the other machines at my location. They only see requests from our local time server.

      • I'm guessing I need to put in a laugh track. I usually turn off the automatic updates, including the time. *Paranoia strikes deep* You'd be amazed at how sloppy these crystals in our machines are at keeping time. 60 cycle hum is more accurate.

        • Back in the Windows 9x days I remember adding a realmode program to autoexec that would compensate for natural drift in the clock. Sync the clock to atomic, sync it again in a week when it was way off, and then it would calculate the error and continuously apply it to the RTC. It worked surprisingly well.

          To bad a similar algorithm is not still used.

          • Re: (Score:2, Informative)

            by Anonymous Coward

            That's essentially what NTP does. It runs in the background as a daemon and disciplines the local clock to keep it in sync with the upstream servers. It won't jump the time unless you tell it to, choosing instead to slow/speed the passage of time to stay in sync.

            IIRC, the amount needed to discipline the local clock is stored in the drift file.

            This all works very well as long as your clock crystal is mostly rational and doesn't jitter too much based on temperature variation.

      • And that is the way it shoud be.

        The only tinhg I'd consider adding would be a level-0-or-1 source, such as a GPS/ GLONASS time source (you can argue over whether that is level-zero, or level-one, validly), and some glue so that if your time system and the alternative system differ by more than $SENSITIVITY$, your sysadmins get an ... orange-not-red flag and are aware of the issue.

        If you're doing very time sensitive work, that's a different issue. A large bucket of issues.

  • by turkeydance ( 1266624 ) on Wednesday March 16, 2016 @02:49PM (#51709833)
    with my technology
  • bzzzzt (Score:5, Interesting)

    by epine ( 68316 ) on Wednesday March 16, 2016 @03:12PM (#51710039)

    TFA:

    the newest of which is so accurate, it gains or loses only a second every 300 million years

    First of all, that's aspirational (or was) in most of the other articles I found.

    Contra TFA: NIST Launches NIST-F2 [nist.gov]

    Primary standards such as NIST-F1 and NIST-F2 are operated for periods of a few weeks several times each year to calibrate NIST timescales, collections of stable commercial clocks such as hydrogen masers used to keep time ... Technically, both F1 and F2 are frequency standards, meaning they are used to measure the size of the SI second and calibrate the "ticks" of other clocks.

    Unfortunately, even contra TFA is weak geek tea:

    Both NIST-F1 and NIST-F2 measure the frequency of a particular transition in the cesium atom—which is 9,192,631,770 vibrations per second, and is used to define the second, the international (SI) unit of time.

    I guess there's a reason why people with tiny UIDs memorize pi to a silly number of places: it helps you not leave off the other five or six significant digits in the rare case where it actually matters. The real frequency standard is only, like, approximately a million times better than that long-assed, dock-tailed string of digits visually implies.

    Truly inconceivable—almost—and yet barely able to time slice the total perspective vortex.

    Finally, some obligatory geek porn: Atomic fountain [wikipedia.org]

    • by KGIII ( 973947 )

      Pfft... Real geeks know (and understand!) the Bailey, Borwein, and Plouffe Formula and a dozen ways to implement it in C.

  • by PopeRatzo ( 965947 ) on Wednesday March 16, 2016 @03:18PM (#51710095) Journal

    I no longer believe in time. I think it's pretty much junk science, and the daylight savings time thing is just an Illuminati plot to keep us subservient to the elite.

    You all can do what you want, and spring forward or what not if you need to bend your will to The Man, but I ain't changed my clocks since 2007 and haven't noticed one thing. In fact, I couldn't change them since I threw out my wristwatch, Easy Rider-style, in 2006. Right now, if I look down at the time display on my screen, it's flashing 00:00:00, just like my DVD player and microwave.

    • by neminem ( 561346 )

      You forgot to mention how we were all educated stupid.

    • Time is an illusion. Lunchtime doubly so.
  • I am using time.nrc.ca as my reference (I don't think it is a stratum 1 however)
  • by pr0fessor ( 1940368 ) on Wednesday March 16, 2016 @03:25PM (#51710153)

    "What time is it?" 6 Billions times a day...

    Sounds like a long road trip with my kids... Are we there yet, How much farther, When will we be there, What time is it

  • I thought trading system typically relied on GPS based NTP servers in their own network?

    Oh and if you want to make your one: http://www.satsignal.eu/ntp/Ra... [satsignal.eu] . While probably not as accurate as a commercial version, it is a tad slight cheaper.

    • by Anonymous Coward

      You'd still need a reference time keeper to ensure there's no drift in your (or even their) systems. Everyone synchronises with the official timekeeper.

      Note: If there was drift in every other system in the world except yours then that will have the inverse effect on you. In fact the earth's slow degradation as a time keeper is why we have leap seconds.

  • by Anonymous Coward on Wednesday March 16, 2016 @05:26PM (#51711023)

    Judah Levine, the gentleman mentioned in the article, built interfaces to existing atomic clocks that allowed other clocks to synchronize with them, which is a worthy achievement.

    But today, the vast majority of synchronized clocks are being kept synced by NTP across the Internet, not by radio signals. And although Levine also implemented NTP interfaces at NIST, he didn't invent NTP nor was he responsible for its dominance of Internet timekeeping.

    The man who invented NTP and originally wrote the implementation was David L. Mills of the University of Delaware.

    Mills is also the man who created the Fuzzballs and EGP, making global-scale internetworking possible.

    • by Ungrounded Lightning ( 62228 ) on Wednesday March 16, 2016 @06:15PM (#51711365) Journal

      The man who invented NTP and originally wrote the implementation was David L. Mills of the University of Delaware.

      Mills is also the man who created the Fuzzballs and EGP, making global-scale internetworking possible.

      I knew Dr. Dave when he was still at the University of Michigan, doing the Data Concentrator and the Language Lab's automation, and I was in high school and hanging around the campus.

      Great guy.

    • Thank you. I deeply lament David Mills's absence from the original article. He should at least have been mentioned, as he deserves far more credit for innovation in distributing time than does Judah Levine, while still intending no disrespect for Dr. Levine.

  • I'm not into time...

I THINK MAN INVENTED THE CAR by instinct. -- Jack Handley, The New Mexican, 1988.

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