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Science Government Politics

Vote To Eliminate Leap Seconds 531

Posted by kdawson
from the making-y2k-look-like-a-walk-in-the-park dept.
Mortimer.CA writes "As discussed on Slashdot previously, there is a proposal to remove leap seconds from UTC (nee 'Greenwich' time). It will be put to a vote to ITU member states during 2008, and if 70% agree, the leap second will be eliminated by 2013. There is some debate as to whether this change is a good or bad idea. The proposal calls for a 'leap-hour' in about 600 years, which nobody seems to believe is a good idea. One philosophical point opponents make is that the 'official' time on Earth should match the time of the sun and heavens."
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Vote To Eliminate Leap Seconds

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  • Wait (Score:5, Funny)

    by Monkeys!!! (831558) on Tuesday November 20, 2007 @03:13AM (#21417603) Homepage
    Just hang on a sec....
  • by r00t (33219) on Tuesday November 20, 2007 @03:19AM (#21417621) Journal
    We call this "putting off the problem".

    We can ignore the problem then too. Eventually, morning and evening will be on different days. We might just gain or lose a whole day. Heck, we can ignore the problem forever. We'll be off by a year, then a decade...

    • Re: (Score:2, Funny)

      by Thanshin (1188877)

      We call this "putting off the problem".

      We can ignore the problem then too. Eventually, morning and evening will be on different days. We might just gain or lose a whole day. Heck, we can ignore the problem forever. We'll be off by a year, then a decade...

       
      Ok guys. We're in California, it's midday 26th June while I have snow falling on my face and I can't see shit because it's new moon.

      How many seconds was it already?
    • by aevan (903814) on Tuesday November 20, 2007 @03:27AM (#21417663)
      In other news, people in 2612 voted to put off the issue of 'leap hours' until 16412, where they propose to add a 'leap day', ostensibly in February.
    • by RuBLed (995686)
      I often experience that too but the solution to the problem is and will always be.. buy new batteries...
  • by hedgemage (934558) on Tuesday November 20, 2007 @03:25AM (#21417649)
    I've been keeping time with my sundial and temple-top observatory the way Ra intended! Damn you kids and your new-fangled timekeeping.
  • by drgroove (631550) on Tuesday November 20, 2007 @03:26AM (#21417655)
    I thought of this issue years ago, and had actually sat down and done the math at one point... basically, to solve the time discrepancy, just slightly lengthen the second. Everything lines up. Of course, every book, piece of software, scientific instrument, medical equipment, ... well, basically everything in human civilization ... would need to be re-build, re-calibrated, re-programmed, re-manufactured, etc. If nothing else, we'd stimulate the living hell out of the world's economy.
    • by mbone (558574) on Tuesday November 20, 2007 @03:57AM (#21417781)
      Of course, the real problem is that the rotation of the Earth is not constant (the leap seconds are mostly driven by fluid motions in the core).

      Originally, back in the 1960's, instead of the leap seconds, they (the BIH at the time) adjusted the rate of the UTC seconds with respect to TAI. This was widely viewed as not a good thing once it was tried and was dropped, IIRC in 1972.
    • Re: (Score:2, Insightful)

      by Mathinker (909784)
      The first AC reply to your idea is correct but I have a feeling you still might not understand his point. The "leap seconds" which we are talking about are not, like the extra days in leap years, always added to the length of the day. Sometimes they are subtracted.

      I am not an expert, but the "exact second" calculation you want to make, averaged over a long enough period of time, seems to me to depend on the motions of every sizeable object in the Solar System and probably also (or maybe even more strongly)
    • Don't have to. (Score:2, Insightful)

      by SamP2 (1097897)
      Yay, nothing like reliving the thrill of Y2K. Except that we don't have to.

      One second in 600 years is about 1/18921600000 or roughly 0.000000005%. In a day, the difference between the two ways will produce an offset of 1/220000th of a second, or about 5 nanoseconds. With the possible exception of atomic clocks, no analog or digital device is this precise.

      Since any "precise" timekeeping requires periodical synchronization with the world's atomic clocks and astronomical observatories, we'd only need to chang
    • Re: (Score:3, Insightful)

      by FireFury03 (653718)
      basically, to solve the time discrepancy, just slightly lengthen the second. Everything lines up.

      You would need to make the second variable length since the leap second is inserted at variable intervals to compensate for the non-constant slowing of the Earth's rotation.
    • by evanbd (210358) on Tuesday November 20, 2007 @10:21AM (#21420609)

      If nothing else, we'd stimulate the living hell out of the world's economy.

      This is the broken window fallacy [wikipedia.org], nothing more.

      Besides, the value of units of measurement lies in their consistency. Changing the second is worse than leap years or leap seconds or leap hours, because any time someone needs a precise measurement, they turn to the second.

  • Other way (Score:5, Interesting)

    by professorfalcon (713985) on Tuesday November 20, 2007 @03:27AM (#21417659)
    How about going the other way... leap microseconds. Many times during the day. Then nobody will hardly notice.
    • Re:Other way (Score:5, Interesting)

      by 4D6963 (933028) on Tuesday November 20, 2007 @05:57AM (#21418343)

      How about going the other way... leap microseconds. Many times during the day. Then nobody will hardly notice.

      Actually it sounds like a good idea. As someone else suggested, the difference due to leap seconds is so small that only atomic clocks are precise enough to need to take them into account. And since we're all synced on atomic clocks anyways we could just make that happen transparently upstream.

      • Re: (Score:3, Informative)

        by Manhigh (148034)
        Space probes/satellites also are sensitive enough to rely on leap-seconds. If you dilute these by breaking them up throughout the day, figuring out ephemerides would be complicated.
    • by dunc78 (583090)
      Yeah, everytime we have a leap second, it really ruins my day. We need something much less noticeable. When was the last leap second again?
  • by maroberts (15852) on Tuesday November 20, 2007 @03:28AM (#21417665) Homepage Journal
    A leap minute every 10 years (or so)?

    One event every 10 years does not cause lots of disruption, and being a minute out of sync with solar time is not large enough to be a problem. You'd notice an hour's difference if you're in a northerly latitude and have Daylight Saving Time...
    • by arth1 (260657)

      One event every 10 years does not cause lots of disruption, and being a minute out of sync with solar time is not large enough to be a problem.

      Except for all the millions of cron jobs that run at a minute granularity.
      If the same minute occurs twice, should the job run twice? If a minute is skipped, should the job not run at all, or run a minute early, or a minute late?

      This is the same problem as the witching hour every year when switching to and from daylight savings time. The remedy for that is to ensure

      • Re: (Score:3, Informative)

        by Tony Hoyle (11698)
        This is the same problem as the witching hour every year when switching to and from daylight savings time. The remedy for that is to ensure you don't schedule jobs for those hours, or get vendor assurance of what, exactly, will happen for jobs scheduled at the start, middle or end of the witching hours.


        Nope. cron, like all Unix services, runs to UTC and doesn't give a crap about daylight savings time.
    • A leap minute every 10 years (or so)?

      Some safety critical real time systems such as radar trackers need an accurate time reference to be able to work at all. They don't care about the time of day but do care a lot about each hour, minute and second being exactly the same length.

      I think we need two references. One time reference which never, ever changes, and another which tracks the diurnal cycle. For the latter, leap minutes would be fine.

  • by rew (6140)
    I live at 5 degrees east. Thus, I know that because I'm at GMT+1, the sun will be exactly in the south at 12:40 PM. If we change to the "leap hour" strategy, I'll have to remember what the offset is now, and that offset will change all the time...
    • Re: (Score:3, Informative)

      by FireFury03 (653718)
      I live at 5 degrees east. Thus, I know that because I'm at GMT+1, the sun will be exactly in the south at 12:40 PM. ...Except the exact time the meridian passes under the sun varies throughout the year since the Earth's orbit isn't circular.

      Don't get me wrong - I think removing the leap second is just silly but your point is rather bogus.

      See http://www.timeanddate.com/worldclock/ [timeanddate.com]
  • by MegaMahr (788652) on Tuesday November 20, 2007 @03:30AM (#21417673) Homepage
    This is why I refuse to set the time on my VCR...
  • by niceone (992278) * on Tuesday November 20, 2007 @03:31AM (#21417685) Journal
    Yeah, because the best way to to deal with a small problem is to put it off until it becomes a really big problem.
    • by SeaFox (739806)

      Yeah, because the best way to to deal with a small problem is to put it off until it becomes a really big problem.

      Hey, it worked for the environment. It's only a problem for those of us still alive in 600 years.
    • by arth1 (260657)
      I see it more of a problem with US legislators trying to govern what's outside human control.
      Congress passing a law that a year is a constant length doesn't make it so.

      Next thing, they'll pass laws stating that zenith is always at noon, or that there will be a full moon every 29 days.

      Regards,
      --
      *Art
    • Re: (Score:3, Funny)

      by jmv (93421)
      Who wants to bet that in 600 years, they'll decide to scrap the leap-hour and instead have a leap-day in 13800 years?
    • Re: (Score:3, Insightful)

      by An dochasac (591582)
      I suggested [sun.com] that everyone on the ITU committee should be asked to read David Ewing Duncan's book "Calendar - Humanity's Epic Struggle to Determine a True and Accurate Year." [davidewingduncan.net] Ponder the fact that it has taken thousands of years of struggles, scientific advancement and setbacks to get human time synchronized with astronomical time. Great rifts developed in societies and wars were fought over the accurate calculation of time. (Check out the Irish/Roman/Orthodox rift over the calculation of Easter). Now wi
  • by Mantle (104724) on Tuesday November 20, 2007 @03:36AM (#21417707)
    ... which nobody seems to believe is a good idea.



    Um... isn't the whole point of this article that some people think it's a good idea? TFS even says there is debate over whether it is a good or bad idea!

    • Re: (Score:3, Funny)

      by Hal_Porter (817932)
      Maybe he's talking about Mr Nobody.
    • Re: (Score:3, Insightful)

      by gstoddart (321705)

      Um... isn't the whole point of this article that some people think it's a good idea? TFS even says there is debate over whether it is a good or bad idea!

      I suspect the people who think dispensing with leap seconds et al are people who don't care about the underlying astronomy that goes into how we calculate time.

      If you don't update your time to match how the actual configurations of orbits and the like works, then your equinoxes, solstices and other fun stuff stop lining up.

      Carried on long enough, Spring wou

  • Actually, the leap second makes the most sense to me. But a leap hour in 600 years, when we do an entire day about every four years is absurd. If we had to abandon the leap second, it should only be replaced by the leap minute,. Likely few people would notice the time being off by as much as a minute (just don't use that sextant any more, or if you do wear two watches or set your to heavenly time). But time being off as much as an hour would pretty much muck things up (think of the effect of daylight saving
  • by damaki (997243) * on Tuesday November 20, 2007 @03:41AM (#21417731)
    Yeah, this 600 years stuff is nice but who will remember to adjust clocks in 600 years? It's far better to have an instantaneous solution to the problem than a remote one.
  • by swamp_ig (466489) on Tuesday November 20, 2007 @03:57AM (#21417783)
    The leap second is required because the earth's spin is slowing down in a complex, non-linear way.

    Changing the length of the second simply won't work, in a couple of hundred years we'll be right back to where we started again. See http://en.wikipedia.org/wiki/Leap_second [wikipedia.org] for details.

    The leap hour is a daft idea, why change something that isn't broken, if a tad inconvenient.
  • by mbone (558574) on Tuesday November 20, 2007 @04:01AM (#21417811)
    ... don't fix it.

    This is a bad idea, and my understanding is that it has not much chance of being adopted.
    • It is broken.

      Leap seconds are lost moments in time depending on the time system you use. Linux time [wikipedia.org] is a good example. Every time there is a leap second Linux time deviates further from UTC.

      In this day and age, do we really have to keep lining up our time system to astronomy events, rather than realizing that time is actually linear, and so should our time system be? Over time our time system will not be perfectly synchronized to every event that happens to occur in the universe, nor should we try to force
  • Leap hour ... WHY? (Score:3, Interesting)

    by Karellen (104380) on Tuesday November 20, 2007 @04:15AM (#21417903) Homepage
    Why have a leap hour in 600 years time? Surely it would be easier for all countries to just change their local time offset to UTC by 1 hour. So, for example, instead of Pacific time being UTC-0800/UTC-0700, it would become UTC-0700/UTC-0600. (Or maybe 0900/0800)
  • How about DST (Score:5, Insightful)

    by Trogre (513942) on Tuesday November 20, 2007 @04:27AM (#21417953) Homepage
    I don't really care what they do with leap seconds, but IMO their time would be better spent abolishing that routine-breaking, parent-killing, accident-causing abomination which is Daylight Savings Time.

    The only benefits I can see is slightly later barbecues in summer and a six-monthly reminder to check smoke detector batteries about the house.
    • Re:How about DST (Score:5, Interesting)

      by julesh (229690) on Tuesday November 20, 2007 @05:51AM (#21418315)
      DST is set by local governments. This is an entirely different thing, an international standards body messing around with time, instead.

      BTW: I'm of the opinion that it's not DST that should be abolished, but non-DST. Non-DST time is a good mathematical division of the day, centred equally around 12:00 (+- 30mins). Unfortunately, as a society, we seem to have decided to centre our actual lives around 13:00 instead. Switching permanently to DST would fix this.
      • Re: (Score:3, Insightful)

        by theCoder (23772)
        Unfortunately, as a society, we seem to have decided to centre our actual lives around 13:00 instead. Switching permanently to DST would fix this.

        Until our society decided to center our lives around 14:00.

        For the past couple summers, I've been protesting DST by simply not changing any of my clocks. It takes a bit to get used to, but once you learn to translate times, it works out. And as someone who doesn't mind getting up earlier in the morning (though I do like to sleep in when possible), it does help y
      • Re:How about DST (Score:4, Interesting)

        by imsabbel (611519) on Tuesday November 20, 2007 @08:08AM (#21419127)
        Its actually even worse.
        You might think of the "9-5" workday when saying that the center is 13:00.
        But in reality, its more like 15:00 (most people wont be a lot of time awake _before_ going to work, but lots of time after...

  • Don't worry, time will lose all meaning by then anyway.
  • by Colin Smith (2679) on Tuesday November 20, 2007 @04:37AM (#21418003)
    Before trains, nobody cared. Very few people care now.
     
  • by SirStiff (911718) on Tuesday November 20, 2007 @04:37AM (#21418009)
    We could just fire off some nukes every six months or year to control the orbital speed of the earth around the sun. Just keep tuning the orbit to our atomic clocks instead of vice-versa.
    • Re:Steer the Earth (Score:5, Insightful)

      by 4D6963 (933028) on Tuesday November 20, 2007 @06:15AM (#21418439)

      We could just fire off some nukes every six months or year to control the orbital speed of the earth around the sun.

      Congratulations, you completely failed to understand the fundamental difference between a day and a year! A feat accomplished by few to this day!

      What defines the day is the rotation speed of the Earth around itself, not the orbital speed around the Sun. Besides, as some other people pointed out, this whole leap second thing is irregular, or if you prefer, one step forward, one step back, because the speed of rotation of the Earth varies slightly.

  • by Anonymous Coward on Tuesday November 20, 2007 @04:39AM (#21418021)
    Run computers on TAI (International Atomic Time). Keep it constantly flowing, and never add or remove seconds, as per the definition. Then simply calculate UTC in software from a published leap offset between the two, which compensates for the leap seconds:

    UTC = TAI - leapseconds

    Then define all the timezones off of UTC as normal. All this basically does, is make the calculations for the timezones into a few hours plus or minus a few seconds. This makes a lot more sense, because then you actually have a fundamental time (TAI) which doesn't have discontinuities, but if you want to consider your astronomical orientation, you look at UTC or your local time. We don't need to redefine these types of time, because these already exist. We just need to use them more intelligently.
    • Re: (Score:3, Informative)

      by odyaws (943577)

      Run computers on TAI (International Atomic Time). Keep it constantly flowing, and never add or remove seconds, as per the definition. Then simply calculate UTC in software from a published leap offset between the two, which compensates for the leap seconds:

      UTC = TAI - leapseconds

      Then define all the timezones off of UTC as normal.

      This is basically what they do in one area I have experience in where keeping precise track of time is important: spacecraft navigation. Ephemeris Time [wikipedia.org] (not actually obsolete as the article claims) is generally referenced as the number of seconds since January 1st, 2000, 12:00:00 TT, is the "official" time that you work with when computing the positions of heavenly bodies (and spacecraft). The transformation from ET to UTC (the human-readable time) changes when leap seconds are added. When using UTC to com

    • Re: (Score:3, Informative)

      by evanbd (210358)
      Interestingly enough, that is exactly the relationship between GPS time and TAI. It's defined the other way, obviously, but GPS time does not have leap seconds, and the GPS signal includes the size of the correction needed so that receivers can display UTC time.
  • Change time (Score:4, Funny)

    by Joebert (946227) on Tuesday November 20, 2007 @04:46AM (#21418055) Homepage
    I think it would be soo much easier to throw away our clocks & base everything on the number of seconds since 00:00:00 January 1st 1979 from now on.

    Come on it's been nearly 2008 years since we had BC, it's time for a change !
  • by D4C5CE (578304) on Tuesday November 20, 2007 @05:00AM (#21418105)
    If one little (leap) second is worth all the fuss, where's the uproar to finally rid us of the dangerous practice of needlessly, senselessly changing almost all clocks in existence (in an age where every other gadget has one) twice a year by one whole whopping hour [wikipedia.org], with all the trouble that entails?
  • by weighn (578357) <<weighn> <at> <gmail.com>> on Tuesday November 20, 2007 @05:17AM (#21418159) Homepage
    sure, [eliminating leap seconds] may save a few lives... but thousands will be late
  • by Televiper2000 (1145415) on Tuesday November 20, 2007 @05:20AM (#21418165)
    I bet it would be a considerable challenge to find 12 watches synchronized within 30 seconds of each other. So we're worried about seconds of mismatch between sundials and the only computer on earth that isn't connected to the internet? I agree with the article. Leave UTC time alone and synchronize to GPS time instead. The rest of the world will go on being happy having their watch within a couple minutes of the "official time."
  • Corollary... (Score:4, Interesting)

    by evilviper (135110) on Tuesday November 20, 2007 @06:23AM (#21418491) Journal
    Inherently, those who want to get rid of leap seconds also want to get rid of time zones (at least they indirectly do).

    Having our clocks NOT agreeing with astronomical time, completely eliminates all the benefits of time zones.

    Whether you actively think about it or not, our sense of direction is substantially driven by the combination of our clocks, and the Sun. We use it as a reference all the time (why do you think it's harder to find your way in a new area, when it's dark?). Even if there's no other defining features, there's still the Sun to tell us which way is North (or South), and our clocks give us a reference to relatively where the Sun should be. Subtly change someone's clocks, and you'll see them having a slightly more difficultly with their (otherwise good) sense of direction.

    Seems to me, the only argument here is that there are a few groups who _really_ just happen to need TAI time, but they see that it's just much easier to access sources of UTC time, and so want to redefine UTC (eliminating leap seconds) so that it is monotonic, and strictly corresponds with TAI at all times. Did I miss anything?

  • Go For It (Score:3, Interesting)

    by tidewaterblues (784797) on Tuesday November 20, 2007 @07:06AM (#21418743) Homepage
    As much as we play around with daylight savings time, more often then not local earth time and the relative position of the sun overhead don't match anyway. More importantly, it has been even longer since most people cared. The philosophical questions are now moot, the scientific and engineering questions have workarounds (no one measures anything serious in local time, they just convert to it), and all that is left is the question of whether or not we need to expend the effort to adjust our clocks every time they are just one second off from some fully imaginary standard.
  • by AB3A (192265) on Tuesday November 20, 2007 @07:20AM (#21418815) Homepage Journal
    The question is what do you want to do with the time of day. Should it be astronomically based? This is not a trivial question.

    Many electric grids are required to be timed with accuracy of better than 10 milliseconds. Remote Telemetry Units need to record events with a time stamp that might mean something to an operations control center. The problem is what do you do with leap seconds?

    The POSIX standard time epoch doesn't include leap seconds. So you're left with a terrible morass of a problem. Do you do what the NTP deamon does, by slewing the clock at some known rate? The problem with that is that while events remain in sequence, the time between events is not accurate. Do you simply include a second 59th second? The problem there is that events will be recorded out of order and they can't be sorted back.

    And yet, many also have legal requirements to adhere to a UTC based time standard.

    Ladies and Gentlemen, the problem isn't the leap-second concept. The problem is our damnable entrenched software standards. We're trying to fix this problem by creating another.
  • by 140Mandak262Jamuna (970587) on Tuesday November 20, 2007 @07:47AM (#21418981) Journal
    The basic idea is not to demand that the year be an integral number of days. The New Year will be "born" at varying times of the day. I clearly remember my mom cooking up the New Years feast and then waiting patiently for the new Year to be born, which would shift by about 6 hours every year. The Hindu calender will state the next new year, "Sowmiyan" or "Sadharanan" (there are 60 named years) will be born at 1:06 PM or 7:36AM or whatever. Typical South Indian New Year will begin on April 14 for about three years (like 7AM, 1PM, 7PM) and on April 15 (1AM) for a year and then the leap year in western calender will bring it back to April 14.
  • by Womens Shoes (1175311) on Tuesday November 20, 2007 @10:01AM (#21420341) Homepage
    I think the best reason they gave for keeping leap seconds is:

    abandoning leap seconds would break sundials.


    Won't somebody think of the sundials!? I mean, c'mon! Sundials are cool and important! And what about Stonehenge?

    Actually, I'm in favor of keeping UT1 and TAI in sync. But not for the sundials :)
  • Obligatory Quote (Score:3, Informative)

    by scruffy (29773) on Tuesday November 20, 2007 @10:26AM (#21420669)
    "It is inappropriate to require that a time represented as seconds since the Epoch precisely represent the number of seconds between the referenced time and the Epoch." - IEEE Standard 1003.1b-1993 (POSIX) Section B.2.2.2
  • by qazwart (261667) on Tuesday November 20, 2007 @10:38AM (#21420847) Homepage
    Keep UTC with the leap second. Civilian time can use that.

    For UT1, eliminate the concept of hours, days, etc. Time will be told by the second only. Maybe even call it something else like a "chron". You can talk about hectochrons, millichrons, kilochrons, etc. In fact, start the counting of "chrons" at January 1, 1970.

    Now, if you use chrons, there is no more link between days or years, and no more leap seconds. Computer systems like GPS or space travel which get thrown off by leap seconds, but don't really depend upon the concept of "day" or "year", can use chrons. People who depend upon the astronomical time can use seconds and live with leap seconds. To each, their own. And, converting between the two units is quite really simple.

    The real silliness of the whole proposal is that these scientists actually think their decision will eliminate the leap second. Astronomers will simply ignore the whole thing and go back to GMT. So will all the governments which means all the atomic clocks will still use leap seconds. UTC will simply disappear, and we're back to square one.
  • by p3d0 (42270) on Tuesday November 20, 2007 @12:10PM (#21422395)
    If leap seconds come too often, and leap hours allow the time to diverge too much, how about leap minutes? Official time doesn't deviate from solar time by much, and yet we only need one every hundred years or so.

    Of course, this doesn't fix the real problem: that the Earth's rotation is gradually slowing, so any system based on a foundation with a fixed number of fixed-length seconds will always become gradually more unwieldy.
  • One thing's for sure (Score:3, Informative)

    by DaveM753 (844913) on Tuesday November 20, 2007 @01:35PM (#21423749)
    No matter how this is resolved, in the end Microsoft will screw-up the time zone patch.

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