Re:Falsehoods programmers believe about Unix time
by endymi0n on Wednesday May 15, 2019 @03:41PM
(#19922979)
That's interesting, I stand corrected. TIL that it's actually a heavily disputed topic and much less clear than I painted it, I had quite a different impression before — thanks!
Re:Falsehoods programmers believe about Unix time
by reitanqild on Wednesday May 15, 2019 @05:31PM
(#19923977)
Happy to see it is not just me that enjoy getting rid of my ignorance : )
Re:Falsehoods programmers believe about Unix time
by lutorm on Wednesday May 15, 2019 @04:30PM
(#19923437)
It's a lot easier to test and prepare for something that occurs at least semi-regularly than a monumental event far into the future that is "so far into the future we don't have to worry about it"....
Re:Falsehoods programmers believe about Unix time
by wmf on Wednesday May 15, 2019 @05:38PM
(#19924041)
If we abolish leap seconds (and any other changes to UTC) and let the error accumulate until it hits 30 minutes then a 1-hour time zone change can adjust for it. Time zone changes happen at least semi-regularly so it wouldn't be monumental.
Re:Falsehoods programmers believe about Unix time
by tinus_hn on Thursday May 16, 2019 @07:02PM
(#19934336)
It would take millennia for such an error to accumulate. Leap seconds are inserted less than once a year and 30 minutes is 1800 seconds.
Re:Falsehoods programmers believe about Unix time
by bloak on Friday May 17, 2019 @09:51AM
(#19939564)
Falsehoods programmers believe about leap seconds: 1. The rate at which leap seconds are inserted will remain roughly constant. [...]
The Earth's rotation is slowing down (by about 2 ms per day per century), so the difference between TAI and UT1 is increasing quadratically, not linearly.
Re:Falsehoods programmers believe about Unix time
by quickthrower2 on Wednesday May 15, 2019 @11:04PM
(#19925802)
Wouldn’t that move the international date line?
Re:Falsehoods programmers believe about Unix time
by wmf on Thursday May 16, 2019 @12:29AM
(#19926125)
I guess so, but I don't know why that matters.
Re:Falsehoods programmers believe about Unix time
by beojan on Thursday May 16, 2019 @07:53AM
(#19928084)
The international date line isn't straight in order to avoid land. Moving it would be problematic.
Re:Falsehoods programmers believe about Unix time
by killjoywashere on Thursday May 16, 2019 @08:19AM
(#19928230)
think of it as ordinal: you're shifting left 1 unit, not moving the line, per se.
Re:Falsehoods programmers believe about Unix time
by thefringthing on Thursday May 16, 2019 @09:07AM
(#19928621)
Still matters because some places want to make sure it's the same day (according to their local reckoning) as it is somewhere else in particular (usually a major trading partner).
Re:Falsehoods programmers believe about Unix time
by beojan on Thursday May 16, 2019 @09:53AM
(#19929047)
Or the next town over.
Re:Falsehoods programmers believe about Unix time
by beojan on Sunday May 19, 2019 @02:23AM
(#19951779)
The other boundaries are a lot straighter.
Imagine what would happen when the International Date Line ends up in the middle of the US.
The US has put forth a proposal to abolish leap seconds. It is now supported by China, Australia, Japan, and South Korea. The ITU keeps punting on actually voting on it - it's now scheduled for 2023.
https://en.wikipedia.org/wiki/Leap_second
A day already drifts... every single day in fact. Why is 0.9 sec the magic threshold for maximum drift? Why can't it be 1 minute of drift, or 1 hour of drift? We are putting out problematic corrections for something a minor drift on the scale of years that should be happening on the scale of centuries or millennia in my opinion.