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The leap second’s time is up: world votes to stop pausing clocks
- canadiantim 4y agoHow does the world vote?
- jgrahamc 4y agoDid you read TFA? It's literally the first line of the second paragraph. The decision was made by representatives from governments worldwide at the General Conference on Weights and Measures (CGPM) outside Paris on 18 November.
- TEP_Kim_Il_Sung 4y agoSo not the world? Title is misleading.
- feet 4y ago>representatives from governments worldwide
- ajkjk 4y agoIt's a totally valid synecdoche. "The world votes..." doesn't mean "every human on earth votes...", it means "a worldwide body votes...".
- orra 4y agoQuite, although even “every human on earth votes” isn’t the most literal interpretation: the planet becoming sentient and itself voting would be. Of course, that’s an absurd interpretation.
- krick 4y agoIt is "a valid synecdoche" only as long as we accept that doublethink and newspeak are desirable. Sure, calling black — "white", dictatorship — "worldwide democracy" and so on… everyone will adjust. And by "will" I mean "already do and always did" — there's nothing new about this, it's just the "truths" we are supposed to believe in are what changes over the centuries, not the way societies work. Perhaps it's even true that there is no other way (which doesn't make me like it any more). So it's totally true that no one is actually mislead by this, but I absolutely understand those who try to pretend they are, and have a slight disdain for those who try to defend this bullshit.
- ajkjk 4y agoI... uh... it's a normal phrase. Dunno know what to tell you. You're not gonna get a lot of takers on this being "bullshit". Feels like you're mad about something big and taking it out on random irrelevant things. There's maybe an argument to be made that using language which implies the legitimacy of organizations as presenting "all of us" is a sort of supremacist way to act, because it casually legitimizes whoever happens to be in power without questioning where they got that power or whether they earned or deserve it. But, like, it's a standards body. If the world didn't have one it would want to go and make one and then be back where we started. This isn't the interesting battlefield for that kind of point.
- echelon 4y agoI would only want qualified people and not laymen voting on this. It's technical, not social. It has little bearing on anyone's lived experiences apart from scientists and engineers.
- yamtaddle 4y agoNobody is confused by this, except those who are trying to be.
- TEP_Kim_Il_Sung 4y agoI am not confused, nor trying to be. It is a factual statement.
- cstejerean 4y ago> The decision was made by representatives from governments worldwide at the General Conference on Weights and Measures (CGPM) outside Paris on 18 November
- nousermane 4y ago...but UTC is still offset from TAI by 37 seconds. Any plans to do anything about that, I wonder?
- deleted 4y ago[deleted]
- nullc 4y agoOnce leap seconds actually stop TAI-UTC will presumably just have a constant offset. Constants are kind of irrelevant since they are very easy to deal with. Really no different than GPS time being exactly 19 seconds off TAI.
- throw0101a 4y ago> How, and whether, to keep atomic time in sync with Earth's rotation is still up for debate. […] > The CGPM — which also oversees the international system of units (SI) — has proposed that no leap second should be added for at least a century, allowing UT1 and UTC to slide out of sync by about 1 minute. But it plans to consult with other international organizations and decide by 2026 on what upper limit, if any, to put on how much they be allowed to diverge. So everything about this hasn't quite been sorted out yet. At some point there may need to be a reckoning like was done with the calendar: > Second, in the years since the First Council of Nicaea in AD 325,[b] the excess leap days introduced by the Julian algorithm had caused the calendar to drift such that the (Northern) spring equinox was occurring well before its nominal 21 March date. This date was important to the Christian churches because it is fundamental to the calculation of the date of Easter. To reinstate the association, the reform advanced the date by 10 days:[c] Thursday 4 October 1582 was followed by Friday 15 October 1582.[3] * https://en.wikipedia.org/wiki/Gregorian_calendar https://en.wikipedia.org/wiki/Gregorian_calendar As annoying as handling a leap second could be, if it happens even somewhat regularly it can be testing more often. Deciding in the future to do a 'one-off' event may be more challenging from both a coördination point of view, as well as trying to handle a rare event correctly in (e.g.) code.
- kps 4y agoThe correct answer is obvious — to stabilize the Earth's rotation — but there are a few implementation details to work out.
- kibwen 4y agoIf we simply detonate the moon it would cease affecting the Earth's rotation, thus solving the problem.
- Mountain_Skies 4y agoYou've created the plot for 'Space: 2099'. Don't let Hollywood steal your idea.
- 4y ago
- nullc 4y agoHurrah! Each leap second event causes hundred of millions of dollars worth of disruption and that's not including the disruption created by leapseconds even when they're not happening (e.g. the frequent false leap seconds) or the mini-disaster we're sure to experience should there be a negative leap second (which we are still trending towards). The delays are unfortunate because it's harder to transition applications that need UT1 to use an offset from UTC when the available time sources are still unpredictably and unreliably leaping on you (since to apply a UT1 correction you need your UT1 offset and your UTC source to agree if and how a leap second has been applied). From a practical perspective it would be better to immediately discontinue leaping, then UTC would immediately become a stable time that adjustments could be applied against for those few applications that need them. It would also save us from a negative leap second.
- ars 4y agoSo we make things worse for humans in order to make it easier for computers? Yah, one second doesn't matter, but it builds up. This: "Or we could even decouple our sense of time from the Sun entirely, to create a single world time zone in which different countries see the Sun overhead at different times of day or night." Shows that they are completely disconnect from human reality: "Science already doesn’t use local times, we talk in UTC." That's great for science, but people care about day vs night.
- soggybutter 4y agoI struggle to understand how we benefit that much from the same wall clock times mapping roughly to the same times of day across time zones. It seems like there's pros and cons to both ways and there's no clear "better" option when it comes to the human experience. Meanwhile, doing away with timezones also does away with a lot of complexity both in computing and other areas (e.g. scheduling across timezones)
- ars 4y agoThis will help you understand: https://qntm.org/abolish https://qntm.org/abolish
- Beltalowda 4y ago> Yah, one second doesn't matter, but it builds up. I don't think it's that big of a deal; do you really care what the perception of "11 in the morning" is for someone 1,000 years ago? This kind of thing is pretty cultural anyway, and a slow drift over a thousands of years doesn't really matter. The main reason we have the "new" Gregorian calendar is because of religious reasons, not because people were having huge practical problems with the old (slightly less accurate) Julian calendar. Plus the current leap second system won't really deal with the long-term drift anyway because the earth's rotation keeps slowing, so in a few hundred years we'd need more leap seconds than the current system allows, and eventually we'd need a "leap second" every day because the day is a second longer (around the year 6000 IIRC).
- 4y ago
- CryZe 4y agoHow is this supposed to work? The rotation of the earth is not a constant. So we either scrap UT1 ("the atomic clock") or UTC ("the calendar"). Neither sound like an actual option. The latter would imply that at some (far off) point in the future you wake up at like 10pm as UTC and UT1 are now entirely mismatched (you may as well get rid of all time zones at that point).
- kibwen 4y ago> The CGPM — which also oversees the international system of units (SI) — has proposed that no leap second should be added for at least a century, allowing UT1 and UTC to slide out of sync by about 1 minute.
- jakear 4y agoIf it gets too bad we can just leap-hour back onto schedule, way easier. (alter the tables that hold the existing offsets - this is done all the time)
- nousermane 4y agoTAI - atomic clock, ignores earth rotation. UT1 - based on Earth's rotation only, strictly 86400 seconds per day; length of each second varies; takes a heck of a lot of effort (and time) to measure accurately. UTC - has same length of a second as TAI, but (for now) tracks UT1 to a precision of +/- 1 second. To achieve that, can have days that are 86399, or 86400, or 86401 seconds long. None of 3 is planned for scrapping. The only change discussed in TFA is to fix UTC day to 86400 seconds (at cost of letting it drift further away from UT1).
- euroderf 4y agoHot take: Leap seconds caused by astronomers refusing to modify their own software, instead getting the rest of the world to modify theirs. Too facile?
- mjevans 4y agoDoesn't astronomy already use their own time reference standard? It seems like JPL (NASA) and the scientific community have defined two currently used sets of time standards for observations from Earth and from space near Earth. https://en.wikipedia.org/wiki/Time_standard#Time_standards_for_planetary_motion_calculations https://en.wikipedia.org/wiki/Time_standard#Time_standards_f... Barycentric Coordinate Time (TCB) and Geocentric Coordinate Time (TCG) with DE430 as the current revision of their standard https://en.wikipedia.org/wiki/Jet_Propulsion_Laboratory_Development_Ephemeris https://en.wikipedia.org/wiki/Jet_Propulsion_Laboratory_Deve...
- dmm 4y agoMore like lazy programmers want everyone to change basic timekeeping practices just so they don't have to fix their code.
- 4str0n0mer 4y agoVery much so. Look at astronomical software, e.g. xephem. There will be a "clocks" tab that displays a number of different clocks, TAI (atomic clock, no leap seconds), UTC (global civil time), media solar time (GMT, which ISN'T UTC) and finally, derived from the aforementioned "sidereal time", which is the one you really need to adjust your telescope. Sidereal time is derived from a year with 1 more day basically, because the earth moving around the sun adds 1 more rotation of the background stars. Which is a drift of roughly 4 minutes per day. https://en.wikipedia.org/wiki/Sidereal_time https://en.wikipedia.org/wiki/Sidereal_time Oh, and then there is stuff like Julian date which you need to look up the myriads of catalogues and tables you need for corrections because everything "wobbles" even more than you'd think. Yes, dropping leap seconds will remove 1 table lookup from the above. But astronomical time systems are so complex that that change is a drop in the ocean.
- 4y ago
- clnq 4y ago> Or we could even decouple our sense of time from the Sun entirely, to create a single world time zone in which different countries see the Sun overhead at different times of day or night. A very interesting idea, but probably much too progressive.
- soggybutter 4y agoI've wanted to do this for years. Every time I mention this to someone I get a surprisingly visceral reaction against it even when they can't think of any real reasons why this would be bad.
- Dylan16807 4y agoI absolutely do not believe that nobody has given you a coherent list of reasons.
- soggybutter 4y agoI didn't say no one ever has, just that there's a very strong negative reaction even when they don't have reasoning for it
- Dylan16807 4y agoDo they really not have a reason or do they not want to put in 15 minutes of effort to explain something that has already been explained a thousand times?
- amflare 4y agoI mean, if chaos is the goal, then sure... Let me refer you to: https://qntm.org/abolish https://qntm.org/abolish
- schlowmo 4y ago> Do normal humans publish "waking hours"? Not typically. I believe I just fell in love with that idea. If this would become a social norm people would maybe stop trying to reach me in the morning. And I would know if it's too late to call others.
- SamBam 4y ago> Leap seconds aren’t predictable, because they depend on to Earth’s natural rotation. This is surprising to me. Is the Earth's rotation so arbitrary?
- bioemerl 4y agoNearly all things in nature spite our systems. The earth even speeds up and slows down in response to stuff like earthquakes and volcanoes.
- a-priori 4y agoYes it varies unpredictably based on changes in the distribution of mass within the Earth from magma flows, air currents, ice pack movements, ocean currents, and so on. https://en.wikipedia.org/wiki/Day_length_fluctuations https://en.wikipedia.org/wiki/Day_length_fluctuations
- gricardo99 4y agoIt would surprise me if we could not measure and detect any variation in the earth’s rotation. A leap second is on the order of less than 0.000001% variation, at least according to the leap seconds applied recently.
- 4str0n0mer 4y agoBasically, things like the weather can influence the speed of rotation. Angular momentum changes when mass is closer to the center of gravity or farther out. That measurably includes mass like water in clouds and leafs on trees.
- mananaysiempre 4y agoMore like the precision of ± 0.5 seconds / year, that is to say 15 parts per billion, is that ludicrous. For comparison, time acceleration in geostationary orbit due to general relativity is somewhat less than one part per billion. Household tools (other than clocks) rarely go beyond a percent, and if you need a particular quantity you don’t have a ready-made tool for you’ll likely going to be hard-pressed to go beyond ten percent. The more precise you want to be, the more complex and numerous physical phenomena you need to consider become; with a system as involved as the Earth, at some point you get to weather-like chaotic behaviour, so no practical amount of additional precision in input data helps anymore.
- bilsbie 4y agoI didn’t vote for this.
- bilsbie 4y agoCan anyone explain what the alternative is? Surely we won’t just get more and more out of synch with the earths orbit? Also why does it say the earth is slowing down but this year it sped up. Sounds quite impossible?
- Hamuko 4y ago>Surely we won’t just get more and more out of synch with the earths orbit? Why does being out of sync with the Earth's orbit matter?
- kangalioo 4y agoBecause humans use time as an indicator for day and night
- bobthepanda 4y agoAlso, historically, we did care about the equinoxes and solstices falling on specific days of the calendar. We may not care anymore, but emphasis on may.
- Vvector 4y agoAnd you can still use UTC as your indicator for day and night. In 100 years, it would only drift around 1 minute.
- Hamuko 4y agoWe don't really do that on a second accuracy though. We need to add a whole new day to the calendar every four years to make up the difference. Meanwhile we've added less than half a minute worth of leap seconds.
- cesarb 4y agoWe already accept an error of half an hour (most timezone offsets are multiples of a whole hour) or more (many timezone boundaries are widened to align with state or country boundaries). A couple of minutes is nothing next to that, and if start getting too far, we can simply redefine the timezone offsets (which we already do twice a year in many places, and any device which might be moved across timezone boundaries already have to deal with that).
- no_butterscotch 4y agoIs this going to make dealing with time/time-zones/etc even more difficult in code now?
- deleted 4y ago[deleted]
- adamsb6 4y agoCurrently software has to be built to accommodate leap seconds. They happen frequently enough that you'll find out within a few years whether your software breaks when time suddenly skips forward or backward. If we kick the can down the road such that eventually we'll need to add a leap minute, we're going to end up with software that was never written to expect time to change in such a way, hasn't had a real world test of the change for decades, and will have no one working on the software who ever had to deal with such a change. It's going to be much worse for software reliability to have a leap minute on the order of once a century than a leap second every few years.
- deleted 4y ago[deleted]
- cptskippy 4y agoIn an enterprise environment, every leap second or TZ change invokes a ceremonious updating of anything using Java or a JVM. I suspect a lot of people would rather perform a once a century update than the bi-annual process they do now.
- MonkeyClub 4y agoDid we just create a Cobolesque Y2K situation for Java? I can just imagine Graybeards of the future rushing ahead of the leap minute to update the JVM lest the world goes in flames yet again.
- gpvos 4y agoThe thing is that there will be entire Java-like ecosystems that will have shorter longevity than the time between leaps. So practically all of them will have no facility for a leap at all.
- nousermane 4y agoYou're right, but I'd argue this problem is already here. Thanks to glaciers melting, earth rotation is (temporarily) accelerating. Because of that, positive leap seconds, regular before, didn't happen since 2017 - so there could very well be (recent) software out there that has that code-path broken, and nobody noticed yet. And due to exact same geophysical effect we might see a negative leap second - something that never ever happened before. What are the odds that every single piece of software gets that one right?
- jasonwatkinspdx 4y agoI'm' baffled by the section about GLONASS. Russia surely has the ability to decide whether they add or remove future leap seconds?
- friend_and_foe 4y agoOf course they do. But government bodies and other institutional bodies incarnated these standards organizations in order to better coordinate with one another, and decided and committed to defering to them a long time ago. Russia is a sovereign state, they can make any decision they want to, but they decided and agreed at some point to defer to this organization for a reason.
- helsinkiandrew 4y ago> Russia is a sovereign state, they can make any decision they want to, but they decided and agreed at some point to defer to this organization for a reason. I think the commenter means that there isn’t a technical reason that GLONASS can’t be changed to not add leap seconds not that Russia doesn’t have to defer to an international body.
- nullc 4y agoIn prior advocacy for the elimination of leap seconds, I found that many of the officials appointed to talk about this stuff are fairly clueless about the engineering. I wouldn't be too shocked if they asked "what uses leap seconds", got an answer, and are advocating on that basis ("We have systems that use leap seconds!"), without having actually asked better questions like "What would require expensive changes if no more leap seconds were issued?"
- puffoflogic 4y agoI trust we will also be getting rid of leap years: that whole pausing the calendar for a day thing is very confusing. Oh wait, that's not how it works. And neither is it how leap seconds work.
- friend_and_foe 4y agoThose are very different scenarios, they aren't equivalent. Leap years have to do directly with the sun, what day and time the equinoxes happen every year and the like. This time noticeably drifts every year, even every day, computers or not. These leap seconds and what not have to do with very sensitive instruments measuring time very precisely. These time measures are entirely about machines.
- puffoflogic 4y agoThat's simply not true at all, and that was my whole point. Leap seconds have nothing to do with precise measurement because they are nothing more than calendar adjustments, just like leap days. They have the same purpose too; leap seconds keep sunrise and sunset in the right place over long periods of time just like leap years keep equinox and solstice in the right place. Note that leap years, an invention millennia old, account for drift on millennial scales, with the 400 year rule for example. This disproves the theory that there is some modern obsession with exactitude which sets leap years and leap seconds apart, because leap seconds too deal with significant drift on the same scales. Only the madness of "smearing seconds" and other workarounds for broken software with incorrect calendar implementations makes them seem different.
- jylam 4y agoIt seems I've got an unpopular opinion reading the comments here, but having some leap seconds from time to time ensure we are able to manage them. But "no leap second should be added for at least a century" ensures there will be a y2k reckoning every century. Seems short sighted to me, even if it is not a game-changing issue, let's be honest.
- charcircuit 4y agoLeap seconds are not useful. We do not need to use them anymore. While yes you are right in that more leap seconds makes it easier to handle leap seconds, it is just better to not have to worry about leap seconds altogother. It is unneeded complexity that helps no one.
- ender341341 4y agoWhy have them at all? how many people do things where they actually matter? at the current rate it'll be ~9000ad before we hit an hour offset, and we do hour offsets twice a year, so if an hour off is okay why is 1 second off not?
- rightbyte 4y agoOk let future generations take the hit. Got ya. Selfish ...
- ender341341 4y agoHow big of a hit is it on the future generation, they can just change their DST, which already happens every few years anyways?
- Stupulous 4y agoThe critical question is whether they'll have to leap forward or fall backward. We simply cannot abide stealing an hour of sleep from our cyborg/transhuman descendants. We'd never live it down.
- andy_ppp 4y agoGreat, now if we could also stop using GMT in the UK and stick to British summer time year round that would be great
- ink_13 4y agoI've never really understood why smearing the leap second is such a big deal. Surely if you have software that is going to be sensitive to small variation in the clock over 24h, you're already not using wall time.
- techdragon 4y agoHot take… Storing anything as UTC was a mistake and we should be using TAI for all storage and computation, only transforming into more human friendly formats for display to end users. This never needed to be a problem except we decided to make it harder to use TAI than UTC and so everything got built up off the backs of legacy bios level hardware supported UTC style clock behaviour, when we should have been using TAI from the start. Yes I know it would have been harder, but we got off our collective asses and decided to fix our short sighted decision making for Y2K date storage, why not this… if it truly costs as much for everyone to endure a leap second why wasn’t it just fixed from the bottom up and rebuilt correctly!
- spiderice 4y agoWhat would using TAI solve exactly? I'm unfamiliar.
- smilekzs 4y agoDatetime storage would consist of two explicit parts: one free from leap seconds (similar to the raw timestamp you get from a GPS receiver), and description of when leap seconds happen, so that you can transform the leap-second-free timestamp into UTC. Feels like a more robust way in principle to me.
- ender341341 4y agoTAI is monotonic clock, and isn't adjusted for solar time of day, it could be considered universal as TAI would be the same between any 2 points, but UTC is adjusted for earths rotation, so a theoretical mars UTC would end up out of sync with earth UTC. EDIT: info below is incorrect about UTC not being monotonic, as pointed out in thread but is useful for monotonic vs non-monotonic: In UTC you can jump forward or back, so it's possible to do an operation after another operation but have a timestamp before it, which is bad for many reasons, top being auditing. do operation one at T0 do operation two at T1 do operation three at T-1 in TAI it would always be do operation one at T0 do operation two at T1 do operation three at T2
- Sniffnoy 4y agoNote that what the article actually says is that there will be no more leap seconds starting in 2035. There could easily still be more before then.
- e63f67dd-065b 4y agoThe full resolution can be found here https://www.bipm.org/documents/20126/64811223/Resolutions-2022.pdf/281f3160-fc56-3e63-dbf7-77b76500990f https://www.bipm.org/documents/20126/64811223/Resolutions-20.... To quote the relevant section: > [the CGPM] decides that the maximum value for the difference (UT1-UTC) will be increased in, or before, 2035 > [CGPM requests that the ITU] propose a new maximum value for the difference (UT1-UTC) that will ensure the continuity of UTC for at least a century I think there are a few possible interpretations of this: - We'll readjust UTC in a century (why would you do this to yourself, please no, nobody wants this) by setting a predicted maximum that'll last 100 years - The maximum is now 1 hour, we'll adjust clocks the same way we adjust for DST - The maximum is infinite, UTC is now TAI + the same integral offset forever I'm hoping for the last one, but who knows. They've once again kicked the can down the road to the next 2026 meeting to decide what the increase in max UT1/UTC difference will look like.
- finnh 4y ago> The CGPM — which also oversees the international system of units (SI) — has proposed that no leap second should be added for at least a century, allowing UT1 and UTC to slide out of sync by about 1 minute. So, in one century, we'll get 1 minute's worth of drift. Recall that we all share the same clock within timezones, and 1 minute of drift between atomic & solar clocks is the equivalent of traveling 1/60th of your timezone's width to the east or west ... something many people do every day as part of their commute. _Everyone's_ clock deviates from their local solar noon, and _nobody cares_. Put another way: (at most) one north-south line in your timezone will have solar noon & clock noon line up. Over time the relative location of that line will move. Fine. Let's not screw with our clocks in an effort to keep the location of that line fixed.
- zokier 4y agoAnd of course there are things like Spain being in utc+1 despite sitting almost entirely west of Greenwich.
- debugnik 4y agoI can barely wrap my head around the idea of living in UTC when I remember that, my friends and I already feel like the sun sets too soon these days. We're just so used to 9:30pm sunsets during summer!
- layer8 4y agoThe problem is mostly (or so I’ve heard) that the drift is relevant for astronomical applications, and they rely on time dissemination which is done in UTC. If UTC decides to start deviating from TAI by dropping leap seconds, those applications will be in trouble. I’m sure that the problem is overblown, but this is the reasoning that was put forward in the past.
- ronsor 4y agoPeople who are using time for astronomical applications will simply have to track the offset if they need to. I'm not sure how that's much more problematic than the current situation.
- Klasiaster 4y agoMost systems rely on network time from a canonical time source. Wouldn't it be enough to do the leap second smearing/adjustment there to free the end systems from dealing with that?
- warbler73 4y agoThe earth sped up slightly the last couple years after only slowing down for a long time. The great leap-minute crisis of 2147 will be interesting.
- hoytech 4y agoIn 2015 I was working at a "fintech" company and a leap second was announced. It was scheduled for a Wednesday, unlike all others before which had happened on the weekend, when markets were closed. When the previous leap second was applied, a bunch of our Linux servers had kernel panics for some reason, so needless to say everyone was really concerned about a leap second happening during trading hours. So I was assigned to make sure nothing bad would happen. I spent a month in the lab, simulating the leap second by fast forwarding clocks for all our different applications, testing different NTP implementations (I like chrony, for what it's worth). I had heaps of meetings with our partners trying to figure out what their plans were (they had none), and test what would happen if their clocks went backwards. I had to learn about how to install the leap seconds file into a bunch of software I never even knew existed, write various recovery scripts, and at one point was knee-deep in ntpd and Solaris kernel code. After all that, the day before it was scheduled, the whole trading world agreed to halt the markets for 15 minutes before/after the leap second, so all my work was for nothing. I'm not sure what the moral is here, if there is one.
- eointierney 4y agoYou did the good job
- Shared404 4y agoThe moral is we get to hear your cool war story. Thanks for sharing! ...okay yeah that's not a moral, but still.
- imglorp 4y agoGreat, here's another. $work had thousands of full custom, dsp-heavy, location measurement hardware devices widely deployed in the field for UTDOA locating cell phones. It used GPS for time reference -- if you know your location, you can get GPS time accurate around the 10's of nanoseconds. GPS also broadcasts a periodic almanac which includes leap second offsets: if you wanted to apply the offset to GPS you could derive UTC. Anyway there were three models of these units, each with an off-the-shelf GPS chip from one of three location vendors you've probably heard of. The chip firmware was responsible for handling leaps. One day, a leap second arrived from the heavens. We learned the three vendors all exhibited different behaviors! Some chips handled the leap fine. Some ignored it. Some just crashed, chip offline, no bueno, adios. And some went into a state that gave wildly wrong answers. After a flurry of log pulling, debugging, console cabling, and truck rolls, we had a procedure to identify units in bad states and reset them without too many getting bricked. It seems the less likely an event is to occur, the less likely your vendor put work into handling it.
- gcanyon 4y agoIt's (less than) a minute a century -- why would we not simply say "no corrections except at the century mark, in the middle of the weekend closest to January 31st"? That way: There's an exact time everyone knows the correction will happen, it's just a question of how big the correction will be. The correction is always in the same direction -- no "one second forward, then later one second back" shenanigans. It always happens over a weekend, so no one has to deal with real-time work-time issues. While maybe some have to work a weekend, at least it's not near the year-end holidays. It only happens once every 100 years.
- dangero 4y agoGoogle does "leap smearing" which seems like the best human solution to this problem: https://googleblog.blogspot.com/2011/09/time-technology-and-leaping-seconds.html https://googleblog.blogspot.com/2011/09/time-technology-and-... standardizing leap smearing algos and constants could work -Bottom layer is atomic clock seconds -We define targeted relationship between current UTC and atomic counter that will occur on a given day and time X -Time is interpolated to drift UTC into place by the given day and time X -Standards body can adjust time on some regular basis by its relationship to the atomic clock and publish the algo to convert from atomic to UTC
- nullc 4y agoLeap smearing is awful except for rough synchronization operations that don't care if you redefine a second, and even there it isn't great even if you know the exact smearing formula because you can't easily tell if the data you're getting is pre-smeared or post-smeared, or should be smeared but isn't, and then you end double smearing or inverse smearing by accident.
- dangero 4y agoMaybe it’s technologically difficult from a standards perspective, but it works well for humans. If the computer smears an extra second into my day, I won’t notice.
- jll29 4y agoThere has been a proposal in the 1950s to the UN by a German mathematician to replace the current calendar by a decimal-based system, in which leap YEARS are not needed either: everything would be divisible by 100. I can't remember where I heard this from, but the anecdote goes he got a reply saying thanks for the proposal, but it is not feasible to introduce such a massive change globally, irrespective of the proposed improvements.
- zokier 4y agoThat is mixing up quite a few different things. World Calendar [1] was proposed in League of Nations/United Nations, but it was created by US person. There was slightly earlier proposal, International Fixed Calendar[2] from British person that also had some popularity. Neither of these were decimal calendars though, that is something from French revolution [3], and even they did not really manage to make it very decimal. Afaik the most vocal opposition to reforms came from the US [1] https://en.wikipedia.org/wiki/World_Calendar https://en.wikipedia.org/wiki/World_Calendar [2] https://en.wikipedia.org/wiki/International_Fixed_Calendar https://en.wikipedia.org/wiki/International_Fixed_Calendar [3] https://en.wikipedia.org/wiki/French_Republican_calendar https://en.wikipedia.org/wiki/French_Republican_calendar
- asdfman123 4y agoThey're just doing this so Twitter won't break, aren't they?
- 1970-01-01 4y agoI didn't get a vote. Did you?
- ummonk 4y agoJust use variable speed seconds.
- shadowofneptune 4y agoThe problem only arose when the second was changed from being 1/86400th of a solar day to being defined by atomic clocks. The old definition worked well for civil purposes but was by the 1950s impossible to accurately co-ordinate between researchers.
- ummonk 4y agoWe have to make adjustments when coordinating anyway since local time anywhere outside sea level needs relativistic corrections to derive global time, so might as well also periodically introduce another adjustment factor based on changes in the rotation period of the earth…
- alerighi 4y agoI never really understood why we need leap seconds. Or better: why we need to bother with them in a computer system at lower level. If we decide that we absolutely need to keep our time in sync with the rotation of the earth, really what should be done is define a timezone with all the leap seconds applied, and use that timezone to only display it to the end user. Not change the way we sync computer clocks for no reason! NTP shouldn't contemplate leap seconds, for example...
- nullc 4y agoWe don't. We were over achieving when they were established. The cost/benefit at the time didn't look so bad because the world wasn't full of distributed synchronized computer systems, so the added 'cost' of leap seconds was just some make work for geeks in national timing labs. The cost benefit is very different today. We can keep civil time roughly aligned with the sun by moving timezones an hour every four to five thousand years. Applications that want to give accurate sidereal time or very accurate sun-up sun-down can use predictions of UT1. Bonus: it's a lot easier to give an accurate UT1 when you don't have to worry that leapsecond (mis)handling has screwed up your underlying clock. That's another part of the cost model that has changed: When leap seconds were created it would have been burdensome to carry around an additional offset in time transmissions for those few applications that want a more accurate mean solar time. But today its fairly easy.
- golemotron 4y agoWe're going to regret this in 10,000 years.
- Giorgi 4y agowait, does this mean there will be no more leap day year starting from 2035?
- ucarion 4y agoThe same CGPM 2022 conference also resolved to give standard prefix names for 10 to the 27 and 30: power prefix symbol 10^27 ronna R 10^−27 ronto r 10^30 quetta Q 10^−30 quecto q c.f. https://www.bipm.org/documents/20126/64811223/Resolutions-2022.pdf/281f3160-fc56-3e63-dbf7-77b76500990f https://www.bipm.org/documents/20126/64811223/Resolutions-20... (Resolution 3, English version on page 23)
- alex_young 4y agoWhy use leap seconds at all? Our current calendar was introduced in 1582, 440 years ago [0]. We add a leap second about every 1.5 years [1]. That means in the time since our calendar was invented, we've added less than 5 minutes to our time. Would anyone notice if noon arrived 5 minutes earlier over the course of 500 years? Especially since the position of the sun varies orders of magnitude more than that simply based on season? Maybe we could all just agree to add 10 minutes in 3022. If we haven't switched calendars again. [0] https://en.wikipedia.org/wiki/Gregorian_calendar https://en.wikipedia.org/wiki/Gregorian_calendar [1] https://www.timeanddate.com/time/leapseconds.html https://www.timeanddate.com/time/leapseconds.html
- jl6 4y agoMan, between this and the Ronna and the Quetta, it feels like science is getting its admin done today!
- selimthegrim 4y agoWell Quetta gets in the news for different reasons for once
- Kronopath 4y agoThat’s because both came from the 2022 General Conference on Weights and Measures of the BIPM. https://www.bipm.org/documents/20126/64811223/Resolutions-2022.pdf/281f3160-fc56-3e63-dbf7-77b76500990f https://www.bipm.org/documents/20126/64811223/Resolutions-20...
- deleted 4y ago[deleted]
- jamesgreenleaf 4y agoLet's fix the root of the problem and make Earth's rotation constant. How hard could it be? /s
- dredmorbius 4y agoWait until you hear about calendrical variability on Venus.
- xivzgrev 4y agowhoopie. Can we get rid of daylight savings time? That one actually kills people https://www.newscientist.com/article/2344401-annual-us-clock-change-kills-33-people-and-36500-deer-in-car-crashes/#:~:text=Moving%20to%20daylight%20saving%20time,costs%20annually%20in%20the%20US https://www.newscientist.com/article/2344401-annual-us-clock....
- blippage 4y agoWell that didn't long, did it? It was introduced in 1972. In years to come historians will be having a good old chortle about how we managed to come up with two times that were 37 seconds apart. In retrospect, fiddling with computer clocks like that was bound to be a nightmare.
- TheRealPomax 4y agoI love how "the world" voted to end the leap second, before actually coming up with how to deal with scientific desync (Real world: irrelevant. Space science: kinda important)
- btbuildem 4y ago> Although human timepieces have been calibrated with Earth’s rotation for millennia, most people will feel little effect from the loss of the leap second. “In most countries, there is a one hour step between summertime and winter time,” says Arias. “It is much more than one second, but it doesn't affect you.” I find this off-hand comment dismissive and out of touch. The semi-annual switch from Daylight Savings to "normal" and back again is absurd, and far from not affecting anyone. Studies show that productivity drops for about a week following the change [1], and there is a marked increase in road fatalities after the clocks are adjusted [2]. If anything, this leap second business is what's irrelevant to everybody except a handful of obscure boffins. [1] https://www.healthline.com/health-news/daylight-saving-can-make-driving-less-safe https://www.healthline.com/health-news/daylight-saving-can-m... [2] https://www.boston.com/news/jobs/2016/03/16/daylight-saving-time-made-you-a-lazier-sloppier-worker-this-week/ https://www.boston.com/news/jobs/2016/03/16/daylight-saving-...
- colinsane 4y agoagreed. i’m sick of being gaslit twice a year when i go to bed, set an alarm for 8 hours from now, and instead it wakes me after 7 or 9 hours while insisting it’s really been 8 hours. it happened again to me just a few weeks ago with the DST switch. i was so mad when i learned that everything had felt off the day of the switch because it was off that i just set all my clocks to UTC. no more gaslighting: my clocks all accurately measure intervals with no tricks, which is exactly what i most want out of my clock.
- nativecoinc 4y agoI wonder: Why is Daylight Savings/Normal Time not implemented using monotically increasing hours? Day goes up to hour 23 one time of year and hour 25 the other instead of doing a clock hour twice. Would be weird to be able to have 23-hour and 25-hour days. But this seems to be how leap seconds are handled (one 61 second minute)?
- leni536 4y agoThat could probably work, but I'm glad that is handled by changing the timezone instead. Otherwise inventors of unix and ntp times would have got the bright idea to rewind or forward those times by a full hour twice a year.
- TheArcane 4y agoNow collectively do the same with daylight saving
- hanafudafan 4y ago
- bilekas 4y agoYay! Another condition to take into account when working with time series and sensitive data across timezones!
- rocqua 4y agoThey suggest world wide UTC, saying that the hours of noon, sunset, and sunrise don't really matter. But the real problem of UTC around Australia isn't the hours but the date. It is really convenient that the date changes whilst we all sleep. It makes 'today' and 'tomorrow' weird.
- c3534l 4y agoI've heard of the endless disruption that leap seconds cause for years and only now have I thought to ask the question: what was so important that the entire world needed to add or subtract individual seconds from the calendar? Seems like you'd need a pretty big justification for something like that, but I only here the horror stories, not what the leap second was supposed to actually solve.
- layer8 4y agoMostly due to tidal friction from the moon, Earth’s rotation is slowing down in the long term. If we don’t adjust our clocks, the difference between the solar day and our clocks will slowly grow, quadratically. See this site for more details and nice graphs: https://www.ucolick.org/~sla/leapsecs/ https://www.ucolick.org/~sla/leapsecs/ In 1972 it was decided that the best way to compensate for this is to insert (and sometime remove) leap seconds, so that the difference between UTC and Earth’s rotation is kept below one second. A certain subset of astronomical and navigational/satellite applications rely on that condition being true. If this is changed, some decades-old systems, some of which may be critical infrastructure, may have to be substantially modified to account for leap seconds in some other way. The mention of GLONAS in the article is one such example. In the international standard body responsible for UTC (ITU-R), there was up to now no sufficient majority in favor of abolishing leap seconds, due to those concerns. (Never change a running system, so to speak.) By now it has become apparent that the benefits of dropping leap seconds should vastly outweigh the potential drawbacks, at least for the next few decades. But it took some time for that realization, and probably also some older participants whose minds couldn’t be changed to die off.
- smegger001 4y ago>If this is changed, some decades-old systems, some of which may be critical infrastructure, may have to be substantially modified to account for leap seconds in some other way. The mention of GLONAS in the article is one such example. GLONAS and other GPS like systems already have to deal with the temporal effects of special AND general relativity in their time keeping. Pushing leap seconds off on to the already special case system seems like a fair trade for making every other programmer and sysadmins life easier. let the extreme corner cases deal with their problems not everyone else.
- bloppe 4y agoI don't understand why this is necessary. We already have TAI (international atomic time) which is just UTC without leap seconds. It sounds like this committee voted to stop adding leap seconds to UTC, but not to "reset" the leap seconds that have already been added, effectively cementing a constant difference between UTC and TAI. What is the point? Anybody who cares about leap seconds should have just been using TAI all along instead of UTC anyway.
- csande17 4y agoThe committee still wants UTC to be periodically adjusted to match the Earth's rotation. They just want to adjust it less often, where "less often" probably rounds to "never" in practical terms.
- bloppe 4y agoHuh, so they want to go from small, frequent anomalies to large, infrequent anomalies. I think "never" is going to be exactly accurate; once we reach 1 minute of offset from astronomical time, everyone will be too afraid to adjust UTC because we'll have had a couple centuries of complacent software written in the meantime. Got it!
- connicpu 4y agoA leap minute once per ~century probably amortizes to a lot less effort. A leap minute is a bigger deal to implement, but you do it a lot less often. And the sun being off by up to a minute isn't a huge deal for humans
- peter303 4y agoThere was talk of REMOVING a second soon because the Earth's rotation had sped up a bit. Physicists havent figured out the cause of the speed up. The previous slow downs were attributed to tidal friction and global warming (expanding seas and atmosphere). https://www.forbes.com/sites/jamiecartereurope/2022/08/03/do-we-need-the-first-ever-drop-second-a-new-wobble-by-earth-caused-the-shortest-day-since-records-began-say-scientists/ https://www.forbes.com/sites/jamiecartereurope/2022/08/03/do...
- cbsmith 4y agoIt seems odd to me that they decision was to not solve it this way, but not how it will be solved going forward. Like, doesn't that effectively make everything more complicated/difficult?
- mqus 4y agoAs another commenter said, we don't get enough leap seconds for it to have a noticeable effect in real life. The solar sync (in this time scale) is really only relevant for space science and they probably need a better time than "adjusting in discrete 1-second-steps" anyways and are much more limited in scope.
- geenew 4y agoI wonder if the idea of giving an irregular offset at regular intervals is in the cards. Having a unknown offset of x seconds every century, say, seems easier to implement than a known offset every unknown interval.
- ZhangSWEFAANG 4y agoDoes anyone find it weird that the General Conference of Weights and Measures has acronym CGWM instead of GCWM?
- akyshnik 4y agoIt's CGPM, from French "Conférence générale des poids et mesures"
- dredmorbius 4y agoThis is also fairly common on international bodies' initialisms for which there are multiple official languages, to not favour any one of them. "ISO" is the International Organization for Standardization, in English, Organisation internationale de normalisation in French, and Международная организация по стандартизации in Russian, its three official languages, as one fairly well-known example.
- 3pt14159 4y agoImagine how we would feel if we adjusted lat-long definitions instead of smearing or leaping time in order to adjust for the slowing down of the rotation of the earth. Does that sound bananas to you? Of course it is. That's what we're doing with leap seconds. Only some people smear and some people leap and they don't even do it over the same time or in perfect synchronicity. Just ditch the leap seconds. They are not worth the cost.
- deleted 4y ago[deleted]
- jeff-davis 4y agoThe first real program I wrote was a forum in perl. But I didn't want to use "advanced" features like "use" (perl's word for importing a module). It just seemed too magical. So, I had limited time manipulation capabilities. I tried to write all the date handling stuff by hand (with a lot of "if" statements for the special cases). I recall trying to make leap seconds work, but not sure if I actually did. It worked well enough for my purposes. Also, no database, so I did it all with flat files. Worked better than you might expect (thanks to built-in flock()), but I wouldn't recommend it.
- taubek 4y agoAnd yet we still have winter and summer time. Is this also a problem? With different rules for each country.
- rmbyrro 4y agoWhy would Russia need 17 years to modify their satellites?
- tsegratis 4y agoSuggestion: Move what is leapsecond independent to UT1, the atomic clock basis -- google, finance, etc now happy Keep UTC etc as is, since offests happen all the time to every other human clock anyway for political or summer time or country boundary changes anyway -- everyone else happy And calculating UTC as offests from the consistent base of UT1 sounds like the way to do it
- cleansingfire 4y agoWe have a GPS time server (so stratum one) that is set to GPS time, so it's off from UTC by almost twenty seconds because they don't ever apply leap seconds. I love it. Another part of the org pressed me to correct my time to match UTC, but I'm so happy to be done dealing with time changes that I just replied "monotonic time" until they got their own. A few grand to not have those problems is such a bargain!