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No leap second will be introduced at the end of December 2026

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Re: No leap second will be introduced at the end of December 2026

#151

Post by Vvector »

pdonis wrote: post #98
Vvector wrote: post #85

Earlier quoted context omitted.

"In other words, we want UTC noon to be within a second of mean solar noon on the prime meridian." Why? If I travel 1 mile east or west of the prime meridian, my solar noon now comes 2-3 seconds earlier/later. It's nearly impossible to have your local time match your local solar noon. For most of the population, solar noon is, on average, 30 minutes off of 12:00 noon. Plus, solar noon varies from day to day by 10-20…

> Why? Um, because it's the prime meridian and that's how UTC is defined? > It's nearly impossible to have your local time match your local solar noon. Which is why I specified on the prime meridian, which is the particular local meridian that UTC is defined as corresponding to. > solar noon varies from day to day by 10-20 seconds. Which is why I was careful to specify mean solar noon. I'm not quite sure what your is…

"But over time, if we didn't have leap seconds, the difference would accumulate. The accumulated difference now between UTC and TAI is 37 seconds--which is almost twice the maximum variation in actual solar noon from mean solar noon that you refer to."

No, the 10-15 seconds I mentioned is the daily variation in solar noon.

From the link I posted, in NYC, solar noon on 2026-01-01 is at 11:59am. On 2026-01-31, solar noon is at 12:09pm. In one month, it has drifted 10 minutes. That's much greater than the 37 leap seconds we have added in 60 years.

"We humans have collectively decided that we don't want that, and that it's better to do the adjustments a little at a time rather than in bigger lumps."

Yet we just reversed that decision. No more leap seconds after 2035. After trying it, we decided it was terrible.

Re: No leap second will be introduced at the end of December 2026

#152

Post by campground »

b112 wrote: post #141
tialaramex wrote: post #70

Earlier quoted context omitted.

2035 is the agreed drop dead date. Everybody agreed that "Leap seconds" are a sufficiently bad idea that they should be replaced by 2035. Nobody has agreed how to fix it, and "Just turn them off" isn't technically legal. However, "What if there were Leap hours instead?" is technically legal and of course those hours would happen in the very distant future (likely after our civilisation is gone) so it's functionally i…

Everybody agreed that "Leap seconds" are a sufficiently bad idea No. Not everybody. I prefer accurate time, and all the complaints I've heard hold little water. My servers need to timesync forwards and back all the time, eg timedrift. They need to jump to new times, or slowly drift, depending. VMs can be hypervisor starved, or need to move to a new host. Servers also need to handle missing time. Any daemon or program…

Accurate to what though, and for what? We decide what the standard is, and it seems like it would be a lot easier to have accurate time if we aren’t adding or subtracting seconds here or there. Does it really matter if the sun crests the horizon a second earlier than it did ten years ago? If it does, isn’t it much easier to just adjust your sun-cresting time?

Re: No leap second will be introduced at the end of December 2026

#153

Post by tialaramex »

dmurray wrote: post #121
BoxOfRain wrote: post #101

Earlier quoted context omitted.

On the subject of amusing British political legislation, should he defeat Nigel Farage in the resulting by-election Count Binface will not be able to wear his costume in Parliament; not only is business attire required in the House of Commons, it's specifically forbidden to wear a suit of armour there due to a law from the 14th century. For those unaware, the major parties have declined to participate in the by-elect…

Quite a few MPs in Westminster already don't take their physical seats in Parliament (and never vote or address the House) because the conditions attached to doing so aren't compatible with their principles. Maybe Count Binface will be the next.

It's understood by constituents that a vote for a Sinn Féin representative is a protest vote that results in specifically nobody going to Westminster to represent you. I cannot imagine that any significant number of people vote for them and are then astonished when this has the effect everybody else expects.

On the other hand, Binface has not, as I understand it, ever said he would not serve if elected. He's made it clear that he's not from Clacton (or Makerfield) -- because he's a space alien -- but I believe he said if he won he would move there so that's fair enough if the constituents want him. They previously elected Nigel, and he's rarely in either parliament or Clacton so Binface can't be worse than that.

Re: No leap second will be introduced at the end of December 2026

#154

Post by duskwuff »

f4c39012 wrote: post #107
tialaramex wrote: post #97

Earlier quoted context omitted.

"Vote Count Binface and Bin the Cunt" :D There's a long tradition in the UK of having electoral candidates who don't expect to win but run because it's free publicity in a high profile race. "Count Binface" is a comedian who dresses up as a space alien whose outfit resembles well, having a Bin for a face. The serious political parties told Nigel to fuck off, if he wants to step down and then immediately contest the s…

I think it's more than publicity. Anyone can stand as a candidate, and anyone can vote for them. Money and connections and establishment and everything else don't matter, all candidates are equal on that stage. It's both weird and to be admired.

And a bit of "if Farage really wants the seat, he can fight for it". There's something unsporting about letting him win unopposed.

Re: No leap second will be introduced at the end of December 2026

#155

Post by creamyhorror »

layer8 wrote: post #140
404mm wrote: post #64

Earlier quoted context omitted.

“Time Lord” could have been used instead of Director. At least once. Please.

Being located in Paris, it would have to be "maître du temps".

Master of Time. One of the Masters of the Universe.

Re: No leap second will be introduced at the end of December 2026

#156

Post by tialaramex »

dooglius wrote: post #132
tialaramex wrote: post #70

Earlier quoted context omitted.

2035 is the agreed drop dead date. Everybody agreed that "Leap seconds" are a sufficiently bad idea that they should be replaced by 2035. Nobody has agreed how to fix it, and "Just turn them off" isn't technically legal. However, "What if there were Leap hours instead?" is technically legal and of course those hours would happen in the very distant future (likely after our civilisation is gone) so it's functionally i…

What does "technically legal" mean here, what authority is that coming from?

The co-ordinated universal time, UTC exists by international agreement. In the 1960s lots of countries signed a treaty so that's the "authority" AIUI.

The treaty says everybody agrees that this new standard will try to track "solar time" which felt intuitively reasonable. They want something equivalent to the old GMT which was really based on solar time, except more modern. At first the idea was, well, we just work out how fast this damp rock spins more precisely and we can use that to ensure everything works forever.

More precise measurements of the damp rock showed that, annoyingly, Mother Nature did not provide the spinning rock as a precise clock, it spins slower and faster according to a huge number of variables and so the best we can do is measure the spinning against an actual clock. So, "Leap seconds" were born to meet that legal requirement to have UTC match the solar time.

The "leap hour" would likewise fulfil this requirement, just in a deliberately useless way because we actually do not care about precisely tracking solar time. If we did, almost every human in the world would be perpetually annoyed because of course our present system of "time zones" means on average we're at least 30 minutes wrong!

Re: No leap second will be introduced at the end of December 2026

#157

Post by pdonis »

Vvector wrote: post #151
pdonis wrote: post #98

Earlier quoted context omitted.

> Why? Um, because it's the prime meridian and that's how UTC is defined? > It's nearly impossible to have your local time match your local solar noon. Which is why I specified on the prime meridian, which is the particular local meridian that UTC is defined as corresponding to. > solar noon varies from day to day by 10-20 seconds. Which is why I was careful to specify mean solar noon. I'm not quite sure what your is…

"But over time, if we didn't have leap seconds, the difference would accumulate. The accumulated difference now between UTC and TAI is 37 seconds--which is almost twice the maximum variation in actual solar noon from mean solar noon that you refer to." No, the 10-15 seconds I mentioned is the daily variation in solar noon. From the link I posted, in NYC, solar noon on 2026-01-01 is at 11:59am. On 2026-01-31, solar no…

> the 10-15 seconds I mentioned is the daily variation in solar noon.

Yes, but averaged over an entire year, it still comes out to zero. The difference between mean solar and atomic time does not. It accumulates over the years.

> we just reversed that decision

We paused it for 100 years after 2035. That doesn't change the physical fact that the Earth's rotation will continue to slow over the long term. We might eventually decide to just not care about that when it comes to civil timekeeping, but that's not what the decision you're referring to did. It just said we can afford to let the difference between UTC and TAI accumulate from 2035 to 2135 (by which time it is predicted to be about a minute) while we figure out what we want to do over the longer term.

Re: No leap second will be introduced at the end of December 2026

#158

Post by _alternator_ »

N19PEDL2 wrote: post #147
_alternator_ wrote: post #50

Earlier quoted context omitted.

In short, yes, the weather, geology, and signicantly, human movement of water via aquifer draining and dam building, as well as glaicial and ice melts, all contribute to unpredictable changes in the earths rotational period, as well as the axis of rotation. The models for this are IIRC trigonometric polynomials of fairly low order, so even if we could model the unpredictability perfectly, truncation error would limit…

> because Russia needed time to update glonass satellites. Why is this? As leap seconds don’t occur on a regular frequency, I assume they are not hardcoded on the software or hardware on board, but the control centre uploads them on the satellites enough in advance once they have been scheduled. So why can’t the control centre just stop sending those updates?

My understanding the problem is that GLONASS is aware of leap seconds at all. It sends messages in UTC, which has this leap second funny business. GPS uses a special "GPS time" (sometimes abbreviated UT) that doesn't have a leap second. For further confusion, the leap second ensures that UTC is never more than 0.9 seconds off of mean solar time, aka UT1.

This type of assumption that was made early in a massive software and hardware project that's now been ossified for ~50 years is going to be hard to change.

Re: No leap second will be introduced at the end of December 2026

#159

Post by recursivecaveat »

wongarsu wrote: post #56
doctoboggan wrote: post #47

Earlier quoted context omitted.

Very interesting, I wonder what happened in 2020 that causes the rotational speed to start drifting the other way? Pandemic -> more people working from home -> less people in tall office buildings -> faster rotation (like a skater pulling in their arms). Probably not remotely true but it would be funny.

Seems like the seasonal change in June-October increased My best guess would be it's somehow related to water distribution? More water going into the atmosphere? Glaciers growing (unlikely)? Did multiple huge water reservoirs go into service and get filled up over the summer months?

I know the Three Gorges Dam added ~0.06 microseconds on its own, so the effect of reservoirs definitely is noticeable. https://www.jpl.nasa.gov/news/nasa-details-earthquake-effect...

Re: No leap second will be introduced at the end of December 2026

#160

Post by firefax »

layer8 wrote: post #136
flexagoon wrote: post #7

Earlier quoted context omitted.

The only better thing is the organization being called "International Earth Rotation Service"

Someone should establish the Interplanetary Sun Orbiting Service.

>Someone should establish the Interplanetary Sun Orbiting Service.

I hope they have one of those logos with a bunch of weird freemason symbols that freak people out.

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