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The leap second’s time is up: world votes to stop pausing clocks

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Re: The leap second’s time is up: world votes to stop pausing clocks

#381

Post by kortilla »

throw827474737 wrote: post #285
kortilla wrote: post #235

Earlier quoted context omitted.

Yeah, they could have been working on something truly valuable like violating people’s privacy with ad-tech. Or maybe sucking millions of hours of people’s lives away with TikTok algo improvements. Maybe they could be working on the next MoviePass! > zero sum game of stock arbitrage. By your definition insurance is zero sum as well. But people find that generally useful. Taking risk off of peoples hands has value eve…

> Yeah, they could have been working on something truly valuable like.... But why not just a reasonable product? Yes, what could that be, there cannot be something that is fairly priced and people really want, need, what just helps. Not today anymore! > By your definition insurance I know what you try there and on a very abstract level you are maybe slightly right, but PLEASE no, high level gambling (==milliseconds&m…

> high level gambling

This is a weasel phrase. Insurance is high level gambling as well. They both use risk models to decide at what price they will sit on the opposite side of a trade for.

Decide where you really draw the line and if it’s time horizons that’s pretty arbitrarily stupid. Insurance uses re-insurance quite quickly to de-risk their own books so pretending trading within a minute vs daily/hourly is pretty silly.

Also, most “fintech” is not the “be the fasted to arb 2 exchanges” variety. It’s usually “be a market maker for products that you can relatively quickly price based on proprietary signals”. If speed is your only advantage, the cat and mouse game will wake you up one day getting beat to the order book on every trade.

> and its pretty clear that fintech here sure doesn't mean the classical bank and modern "normal" payment system...

Not sure where you got that from. All of this is interconnected. The “classical banks” are all participating in deep fast moving bond markets. JPM doesn’t send their orders to some old timey trader with a cigar and a bowler hat via telephone. They use fintech like the rest of the industry.

Re: The leap second’s time is up: world votes to stop pausing clocks

#382

Post by afiori »

codetrotter wrote: post #287
yreg wrote: post #259

Earlier quoted context omitted.

>Sometimes the best solution is not a technical solution (“halt the markets for 15 minutes before/after”) We've had an election recently, right on the day when DST changed. On the night of counting of the votes, the clock went 2:59 AM -> 2:00 AM. To save themselves trouble the Statistics Office instructed all vote counters that under no circumstances are they to enter or update anything in any system during the repea…

The interesting thing about DST is that it's not really repeating the hour, if you include the time zone offset in your time stamp. Here, look. Using the time zone for Norway in this example, with the `date` command on macOS. First the last second before DST ended in Norway this year. TZ=Europe/Oslo date -I seconds -jf %s 1667091599 2022-10-30T02:59:59+02:00 Then the second after. TZ=Europe/Oslo date -I seconds -jf %…

The problem is that nobody does it, for example no DB (AFAIK) does it, they all store dates as something like a Unix timestamp.

And for a lot of things problems would be solved with +01:00 offset while for others you actually want Europe/Berlin offsets

Re: The leap second’s time is up: world votes to stop pausing clocks

#383

Post by afiori »

the_black_hand wrote: post #375
divbzero wrote: post #251

Earlier quoted context omitted.

This is a good story regardless, but if you do want to derive some morals from the experience: – Seemingly simple tasks can be more complex than you expect (“add a leap second on this Wednesday”) – Real world systems can be more complex than you expect (“bunch of software I never even knew existed”) – Planning and testing can make a big difference vs. just winging it (“a bunch of our Linux servers had kernel panics f…

> Sometimes the best solution is not a technical solution (“halt the markets for 15 minutes before/after”) I'm little confused. How does this solve the problem? If you don't code for the second, you'll still be off if you wait. I'm I missing something?

The code to keep your clock in sync is "easy".

They had done it all the previous leap second during the weekend.

The hard part that required a lot of work was making sure that nothing breaks when it happens.

In this case they chose to have a mini weekend in the middle of the week for convenience

Re: The leap second’s time is up: world votes to stop pausing clocks

#385

Post by rajlego »

Konohamaru wrote: post #145
hcrisp wrote: post #115

Earlier quoted context omitted.

Reminds me of the story of the computer engineer at Data General in Traccy Kidder's nonficion book, "The Soul of a New Machine" [0], who quit after spending weeks toiling away on sub-second timing concerns: > He went away from the basement and left this note on his terminal: "I'm going to a commune in Vermont and will deal with no unit of time shorter than a season." [0] https://en.m.wikipedia.org/wiki/The_Soul_of_a_…

Maybe he should get Stephen Colbert's second-by-second day planner.

woah, do you have a link on that? I use plan [1] which is great for minute level planning but also annoying in various ways, if there's other software that can do similar, would love to try it

(i'm guessing that this was purely a joke and no such thing exists)

[1] https://help.supermemo.org/wiki/Plan

Re: The leap second’s time is up: world votes to stop pausing clocks

#386

Post by afiori »

semiquaver wrote: post #354
throw827474737 wrote: post #285

Earlier quoted context omitted.

> Yeah, they could have been working on something truly valuable like.... But why not just a reasonable product? Yes, what could that be, there cannot be something that is fairly priced and people really want, need, what just helps. Not today anymore! > By your definition insurance I know what you try there and on a very abstract level you are maybe slightly right, but PLEASE no, high level gambling (==milliseconds&m…

Most HFTs primarily engage in market making (matching buyers and sellers) which absolutely is a very useful and necessary function to society unless your position is that markets should not exist. https://en.m.wikipedia.org/wiki/Market_maker

You could hold the position that markets are good but not everything should have a market.

For example you can forbid futures and derivatives without forbidding good old stock trading.

Re: The leap second’s time is up: world votes to stop pausing clocks

#387

Post by benlivengood »

eternityforest wrote: post #299
benlivengood wrote: post #167

Earlier quoted context omitted.

As spacecraft start making return trips to Earth we'll run into similar adjustment problems because TAI doesn't progress at the same rate at different altitudes and accelerations, so there'll need to be a re-sync at some point. Satellites already have a similar problem but can just use direct synchronization with Earth since it's so close. In theory spacecraft could do the same direct synchronization to Earth time, b…

Right now there are no people outside Earth's gravity well for significant time. As long as the Earth exists and you can communicate with people there, there's no practical reason not to use an earth based reference clock.

Most of the accurate timekeeping is needed by computers, not humans. We can always define local human time with an affine transform from a coordinated monotonic clock.

Re: The leap second’s time is up: world votes to stop pausing clocks

#388

Post by Konohamaru »

rajlego wrote: post #385
Konohamaru wrote: post #145

Earlier quoted context omitted.

Maybe he should get Stephen Colbert's second-by-second day planner.

woah, do you have a link on that? I use plan [1] which is great for minute level planning but also annoying in various ways, if there's other software that can do similar, would love to try it (i'm guessing that this was purely a joke and no such thing exists) [1] https://help.supermemo.org/wiki/Plan

It was from a skit on the Colbert Report (can't remember the episode). He talks about how NASA added a leap second and then pulled out this comical "second-by-second" year planner and said his plans are ruined because he doesn't know what to do with the extra second. Wish I could remember it.

Re: The leap second’s time is up: world votes to stop pausing clocks

#389

Post by afiori »

colinsane wrote: post #355
Galanwe wrote: post #340

Earlier quoted context omitted.

I agree with your separation between "duration" and "absolute point in time". But it doesn't solve the issue, because durations are often computed as the difference between two absolute points in time. You could get over this on your local machine with a local counter, but across network boundaries you need to rely on absolute differences.

> But it doesn't solve the issue, because durations are often computed as the difference between two absolute points in time. other way around. e.g. unix time is determined by the number of seconds (as experienced by some point fixed to Earth, roughly) relative to some reference point. duration is the native format for most time systems, like UTC, because “absolute time” isn’t a thing that can be measured. faking the…

I regret that the reality is such, but Unix timestamp are in sync with UTC so they too have gaps and reapeats (for positive and negative leap seconds)

The international standard for monotonic time is TAI, which never had leap seconds, but which is also used by almost no one

Re: The leap second’s time is up: world votes to stop pausing clocks

#390

Post by terminal_d »

hoytech wrote: post #103

In 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 assig…

Wow. You should write a post about it that goes deep into what you had to do to make it work.
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