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Comment by maxnoe | Hacker News Reader

* That's why there's UT1 and TAI for different purposes.

UTC is a (strange) compromise between both: ticking SI seconds like TAI but being kept within 1 second of UT1.

As I see it, UTC is an excellent compromise for the purpose of civil timekeeping. But it would be easier in future if computers would use TAI internally and convert to UTC for display.

As the article points out, what is being broadcast to keep systems synchronized is UTC, and TAI only exists on paper, or as derived from UTC. (Note that even if you have an atomic clock, that isn't TAI. TAI is some average of atomic clocks distributed over the earth, due to gravitational and hence relativistic differences.) UTC is effectively our master clock, and changing that would require a large number of technical and legal changes. So it's much easier to just increase the DUT1 tolerance and stop having new leap seconds.

UTC solves nothing for civil timekeeping, compared to TAI.

Timezone bands are massive. If they were perfectly straight (they aren't) then civil time in any one place would be off by up to 30 minutes in either direction, depending on the location. In reality they line up with political entities instead, creating even larger discrepancies (with the extreme case being China, where some regions are hours off).

Compared to that, a second every couple of years is completely irrelevant.

Not to forget the political push to adopt offsets that don't even match correctly. Instead you know fixing the timetables and rules in single go, if that effect is wanted.

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