Vote To Eliminate Leap Seconds 531
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."
Wait (Score:5, Funny)
Re:Wait (Score:4, Funny)
Re:Wait (Score:4, Funny)
year 2612 bug anyone? (Score:4, Insightful)
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...
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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...
How many seconds was it already?
Re:year 2612 bug anyone? (Score:5, Funny)
Re:year 2612 bug anyone? (Score:5, Funny)
Re:year 2612 bug anyone? (Score:5, Funny)
30 Febuary (Score:3, Informative)
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Re:year 2612 bug anyone? (Score:4, Insightful)
Basically, you compute what time of day it is based on your clock ticks and the orbit and spin of your planet. You don't need to model the entire orbital mechanics of your planet... if you think about it that's what all "time of day" systems do now... highly simplified models of the Earth in space. We know that the earth will be inside the zone of space we call "November" and we know it will be turned to the position we call 6am UTC when the clock ticks out this number or any number in this modulo. As we become more demanding of time and more exacting of the position of the planet in space we need to make more sophisticated orbital models... or allow for heuristic adjustments to existing look up table based models.
Time as in time-space has nothing to do with any of this and it is passage of time in space that a computer should be worried about keeping inside itself... not where the sun is. If you want "where is the sun?" you should be use a conversion or algorithm to calculate "where is the sun?" and the "time" inside the computer should be seen as the number of clock cycles that computer has experienced. Using clock ticks alone, your computer can probably do a fair job at guessing at where the sun is... but that's not what computer time is about.
Of course, these ideas neglect relativity. Eventually we'll have to deal with relativity and clock ticks. I suppose you would have to decide on an a set of arbitrary points in the cosmos and call their inertial frame of references "fixed" which you would use to compute temporal differentials via a kind of relativistic triangulation... say clocks in three star systems that transmit their time beats out to the universe and based on the time you read from each at your point in space you can triangulate your position and time-shift due to relativistic effects. But I think I may be getting a few centuries ahead of myself.
And, it doesn't matter what I think anyway. It's not like anybody in a position to influence these decisions and ideas reads Slashdot. If you started now you could probably get all the digital clocks in the world to work on these principles in about a hundred years.
Chrono-noobs! (Score:5, Funny)
Why not just make each second a little longer? (Score:5, Interesting)
Re:Why not just make each second a little longer? (Score:5, Informative)
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.
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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)
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:Don't have to. (Score:5, Informative)
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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.
Re:Why not just make each second a little longer? (Score:4, Insightful)
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)
Re:Other way (Score:5, Interesting)
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.
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Leap Seconds Ruin My Day (Score:3, Insightful)
What would be wrong with (Score:5, Interesting)
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...
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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
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Nope. cron, like all Unix services, runs to UTC and doesn't give a crap about daylight savings time.
Re:What would be wrong with (Score:5, Informative)
Worse, different systems have different implementations. There's bsd, sysv and vixie's implementations, plus numerous variations, and all seem to do their own stuff.
An example: You have four boxes located in the
Which of the three jobs will run on each box on March 30, 2008?
Which of the three jobs will run on each box on October 26, 2008?
Which of the three jobs will run twice on October 26, 2008?
If anyone (except perhaps Arthur D. Olson) can answer that without investigating, I'd be very surprised.
Sometimes the vendors themselves can't say for sure, due to the time adjustment occurring in a different process, and depending on availability of interrupts and CPU time on the system, the cron interrupt may see either the old time or the new time when it wakes. One of the above vendors thus recommends that jobs scheduled for the start/end of the witching hour are moved one minute outside it.
Anyhow, the parent to your post deserves to have the "+1 Informative" stripped, because it's plain misinformation.
Regards,
--
*Art
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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.
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South. (Score:2)
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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]
This is why... (Score:5, Funny)
A 'leap-hour' in about 600 years (Score:5, Insightful)
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Hey, it worked for the environment. It's only a problem for those of us still alive in 600 years.
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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
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We already solve this soon today, so we aren't being stupid like that.
See also the article for this reason to this proposal.
Please take some care with editing... (Score:5, Insightful)
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!
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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
leap minute (Score:2)
600 years? Who will remember? (Score:4, Funny)
What a number of people don't realize... (Score:5, Interesting)
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.
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If it ain't broke... (Score:3, Insightful)
This is a bad idea, and my understanding is that it has not much chance of being adopted.
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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)
How about DST (Score:5, Insightful)
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)
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.
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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)
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...
2013? (Score:2)
This is a modern problem (Score:3, Interesting)
Steer the Earth (Score:4, Funny)
Re:Steer the Earth (Score:5, Insightful)
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.
Simple and accurate solution (Score:5, Insightful)
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.
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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
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Since when has "ample warning" helped? <points at Y2K and the IPv4 address shortage>
No, everyone leaves these problems until the last minute and then runs around trying to prevent the sky from falling in, even if they are known about years in advance.
Change time (Score:4, Funny)
Come on it's been nearly 2008 years since we had BC, it's time for a change !
While you are at it: "Down with DST!" (Score:3, Insightful)
not quite oblig. Simpsons quote (Score:3, Funny)
Synchronize your watches? (Score:4, Insightful)
Corollary... (Score:4, Interesting)
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)
The problem isn't leap seconds (Score:4, Insightful)
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.
Go for the Hindu Calender. (Score:3, Interesting)
My Favorite Reason (Score:3, Funny)
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)
Seems Easy Enough to Solve (Score:5, Insightful)
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.
What about leap minutes? (Score:3, Interesting)
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)
Re:Metric time? (Score:5, Interesting)
Decimal time always reminds me of the scene in Metropolis with two clocks on the office wall [wikipedia.org] -- a 24-hour clock and a 10-hour clock (the length of the workers' shifts).
Re: (Score:2, Interesting)
Decimalisation is over-rated anyway. People think it makes all the sums easier. Does in some ways, but for everyday life, other systems are easier. We used to have 120 pence to the pound in the UK. Much simpler when divvying up the bill at restaurants. Try dividing 100 by three people, four people, six people. Now try it with 120 or multiples thereof. But what about five and ten? Yeah - much harder with 120 (sarcasm).
Anyway, this ignoring the leap second is sounds like the usual case of wishful thinking
Your post - Bollocks (Score:5, Informative)
There were 240 pence to the old (pre-decimalisation) pound, comprised of 20 shillings each worth 12 (old) pence. Do you remember guineas, crowns, half-crowns, shillings, tanners (6-penny piece), threepenny bit, pennies, half-pennies, farthings (a quarter penny)? I do. I suspect that I am quite a bit older than you and I cannot ever remember there being 120 pence to the pound. So either please provide a citation or confess that you are mistaken/talking bollocks. :-)
But the main thrust of your post was correct with regards to dividing sums of money easily. Or at least it was until the education system decided that mathematics and mental arithmetic were not the most important subjects in life. I'm not sure how some of today's young people could cope with such problems.
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But the main thrust of your post was correct with regards to dividing sums of money easily. Or at least it was until the education system decided that mathematics and mental arithmetic were not the most important subjects in life. I'm not sure how some of today's young people could cope with such problems.
12 is a nice number, but I will not support it for a standard until we grow another pair opposable thumbs.
Young people today are nothing compared to what is to come. e-ink restuatant bills that calculate the price for everyone, and even takes into account if you had 2 drinks or 3.
Give another 50 years, and what we call basic math will be indistinguishable from magic for large parts of the population.
Re:Your post - Bollocks (Score:4, Interesting)
From the article..There are two people, Tina Farrel and a sales assistant that need to be darwinised.
Re:Your post - Bollocks (Score:5, Interesting)
Personally, I think the people who judge other people fit to be "darwinised" - especially based on a page-long Web article - are the ones we could do without, rather than the people who's worst known flaw is that they can't count below zero.
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Back on topic, why do you think the Babylonians used Base 60 [wikipedia.org] for things like minutes, seconds? Some cultures knew what they were doing...
Some numbers... (Score:5, Funny)
That would be an interesting transition period as people got used to indicating or recognizing the numbers 4 or 128...
Re:Some numbers... (Score:5, Funny)
Take one hundred
Binary add thirty two
Fingers say fuck you
Re:Some numbers... (Score:4, Insightful)
Re:Metric time? (Score:5, Funny)
Re:Metric time? (Score:4, Insightful)
Chinese didn't "invent" decimal time. Phrases like "in the 1/10000 th part of a chand" and words like paramchand (not accurate transliteration; chand = second) etc., are very common in Sanskrit text. Add the fact that Decimal system itself was invented in India only means that Decimal time was "invented" in India.
Why I am using double-quotes for "invented"? Because no one can invent time. As a human you want to divide time to keep track of it. And you can only do that using the numeral system you know! Indians knew decimal system so they divided it into factors of 10, Sumerians used sexagesimal system, so they divided it into 60.
It is not the division that bears any importance in invention. It is the device which one can use to measure. If you don't have clocks to measure 1/10000 th part of second, it means nothing to write it down. Ancient Chinese are no different.
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Re:Metric time? (Score:5, Funny)
The smallest unit is the "Moment", and then the "While" (or, less used, the "Whilst"). A while is about 14.4 moments. Then you have the "long while", which is 13.8 whiles, then the "time", and "long time"...
For example, it took me a while and three moments to write this comment. I'm not a quick typer...
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As in, "I find your lack of leapsecond-accuracy disturbing..."?
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Re:Metric time? (Score:5, Funny)
Bam (Score:3, Funny)
Yup. (Score:2, Informative)
But that's just the start:
How do we know they're not constant? Because we can measure the variation using atomic clocks, of course.
Re:Yup. (Score:5, Insightful)
What is a year?
Is it the time from perihelion to the next perihelion?
Is it the time from zenith on the shortest day to zenith on the shortest day next year?
Is it the time for when a star within our galaxy is in the same position again?
Is it the time for when a star outside our galaxy is in the same position again?
The earth's orbit rotates, and the solar system rotates, in a galaxy that rotates. And speculation is that the universe rotates too.
Re:Yup. (Score:5, Funny)
Wrong question (Score:3, Insightful)
The real question isn't what is a year, but "what is a day". Measurements were taken of the length of the "mean solar day", which is the average time between noons, which itself varies over the course of a year due to the elliptical shape of the Earth's orbit. (Because we're closer to the Sun during the Northern Hemisphere winter, we're revolving faster but rotating at the same speed, so the time between true astronomical noons is slightly longer than in the summer.)
That length was divided
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Because the duration of the mean solar day / 86400 is not a constant. That was the whole point of the definition of the SI second.
Re:They have to add a leap something, sometime (Score:5, Informative)
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because a non-constant second would make most of physics a serious pain. Basing such a fundamental unit the ever changing motion of a ball or rock in space seems rather silly too.
The underlying cause isn't that we end up with a fraction of a second left over due to the Earth's rotation time not being an integer multiple of a second, but because the Earth's rotation is slowing down.
A second was defined as 1/86400 of the tim
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Yeah, but good luck in getting the typical congressman to understand what non-deterministic or non-linear means, or even admit that they don't know it.