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0 pointsmananaysiempre4mo ago0 comments

> Those who absolutely must have monotonic time

... shouldn’t be using a Unix timestamp, or anything else that’s not a count of SI seconds elapsed since a fixed reference point, to begin with.

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bobmcnamara4mo ago

Pitch: TAI

mananaysiempreOP4mo ago

Kind of. If you “absolutely must” have monotonic time, though, and also care about NTP, then just pointing to TAI (in DJB’s naïve definition) or GPS time is not enough. You need to make decisions on whether you, for example, would prefer your imprecise seconds to be more even individually or for the aggregate count to be more accurate (NTP of course gets you the latter by default). Dear Sir[1], you have done metrology.

[1] https://people.csail.mit.edu/rachit/post/you-have-built-a-co..., https://news.ycombinator.com/item?id=29891428

bobmcnamara4mo ago

I really just want the software time to be as good as the underlying hardware clock...

...rather than setting a rather awful minimum performance spec of 10ppm smearing over a leap second day.

Three lies: Universal - multiple smear implementations, linear vs cosine off the top of my head.

Coordinated - whose in charge here? Google? Facebook?

Time - doesn't even try for 1s/s

UTC is, for all intents and purposes, yet another human readable time zone. And should be treated as such. The underlying hardware problems I have and understand. Don't need the software making it worse.

j / k navigate · click thread line to collapse

0 comments

bobmcnamara4mo ago

Pitch: TAI

mananaysiempreOP4mo ago

[1] https://people.csail.mit.edu/rachit/post/you-have-built-a-co..., https://news.ycombinator.com/item?id=29891428

bobmcnamara4mo ago

I really just want the software time to be as good as the underlying hardware clock...

...rather than setting a rather awful minimum performance spec of 10ppm smearing over a leap second day.

Three lies: Universal - multiple smear implementations, linear vs cosine off the top of my head.

Coordinated - whose in charge here? Google? Facebook?

Time - doesn't even try for 1s/s

j / k navigate · click thread line to collapse