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Comment by michaelt | Hacker News Reader

> One 'answer' to this concern is to have a 'leap hour' or something in the future

We've had 27 leapseconds in the last 54 years [1] - an average of 0.5 seconds per year.

At that rate, solar time will drift by 60 seconds over the course of 120 years. Drifting by 10 minutes will take 1200 years.

The leap hour will be in 7200 years, around year 9226.

[1] https://en.wikipedia.org/wiki/Leap_second

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> The leap hour will be in 7200 years, around year 9226.

7200 years ago the Neolithic revolution was still in full swing and many of the most famous megaliths like Stonehenge hadn’t even been built yet. The first real state, the Sumerian civilization, hadn’t formed yet in Mesopotamia.

Personally, I’m very comfortable making this someone else’s problems 7200 years from now. If they’re still having basic coordination issues then it’s their own damn problem.

"Basic" made me lol :)

"And so the Y10K problem was born"

I’d better go brush up on my COBOL

Programmer-Archaeologist will be quite a coveted position 300 gigaseconds from now.

I just had a Y10K problem. Customer data was using 9999-12-31 23:59:59 as a placeholder value, and our app crashed converting from the customer's timezone to UTC. I learned that Python datetime can't handle Y10K.

> 7200 years ago the Neolithic revolution was still in full swing

Older folks at Göbekli Tepe grumbled that climate change wasn't real. As far as they were concerned, the Sumer and Indus Valley kids were playing with fire and didn't know squat. The older generation just couldn't understand the crazy architecture over in Egypt and the slangy "new wave" movement at Salisbury Plain. It always seemed that the shiftless youth there just loitered and smoked and invented new expressions to frustrate communication. And everyone could agree that no one liked their so-called music!

https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe

https://en.wikipedia.org/wiki/8.2-kiloyear_event

https://en.wikipedia.org/wiki/Sumer

https://en.wikipedia.org/wiki/Indus_Valley_Civilisation

https://en.wikipedia.org/wiki/Old_Kingdom_of_Egypt

https://en.wikipedia.org/wiki/Stonehenge

You're missing that the frequency of leap seconds is accelerating over time, because Earth's rotation is slowing down. The leap hour will therefore happen earlier: https://www.ucolick.org/~sla/leapsecs/future2100.svg

Yeah. There’s also the issue that the earth’s rotation is slowing down, so over the long term leap seconds would become more and more frequent. There’s a point when the earth is slow enough that leap seconds need to happen nearly every month, and by that point they are no longer a workable solution to the problem. That is expected to take a few thousand years, comparable to the point where a leap hour would be needed if there were no leap seconds.

So some future generations might get 23 hour days? That’s gonna be an interesting problem to solve for calendar implementations

25-hour days.

As another poster already said, there will be 25-hour days at some time.

The dinosaurs had days with fewer hours than us.

Where there fewer hours or were those hours just different length?

Now we have locked in second extremely hard underpinning all of our measurements. But you could consider that you have same number of hours in a day and length of those hours has changed...

You could look at it either way. I couldn't say which system the dinosaurs actually used.

I have it on good authority they just used unixtime for everyone but put all the leapseconds in the tz table.

A Martian sol (day cycle/rotation) is > 24 hours (by about 40 minutes). Locked in seconds seems to be the easiest for general use mathematically. 24 hours in a day is a bit of a leftover from sundials and 12 being one of the easiest large fractions of a circle and the Earth day was never really a universal anyway, just an accident of where and roughly when we lived. On the other hand, the modern metric second is now defined at exactly 9,192,631,770 periods of Cesium-133 for atomic clocks and other reasons, so a locked second is useful for a lot of reasons.

> The leap hour will be in 7200 years, around year 9226

You mean 09226, I believe. [1]

[1] https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...

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