5 ms·

If you stop thinking about time being wrong from what is officially correct, and instead see this whole exercise as a error minimization framework I think it is

If you stop thinking about time being wrong from what is officially correct, and instead see this whole exercise as a error minimization framework I think it is far easier to make the case for ending leap seconds as it is for keeping them. This isn't just about lines of missing code. This is about forcing subterranean or submerged computers to surface. This is about out of sync clocks across information propagation networks across planets. This is about real lives that are ruined because time stamps didn't quite line up, causing delays, deaths, and needless headaches. It doesn't need to be this way. We could just accept a minute of the clock being off from "true" midnight, which doesn't even make sense to me given that few people are right at the astronomic point where midnight is "true" midnight for their timezone. Heck, China is one big giant timezone so who is this actually for, really? The people that care about sundials? Most people don't even grow their own food. We're no longer a sun-driven economy. Well coordinated timekeeping across devices that may not always be able to transfer data is far, far more important. If it's sufficiently wrong by the year 3422 then we'll deal with the fifteen minutes of annoyance then. This is a crazy premature optimization.

toast0 4y ago
> Well coordinated timekeeping across devices that may not always be able to transfer data is far, far more important. How do you have a well coordinated clock without being able to get four bits [1] per year of leap second data? It's hard to keep within one second of a time standard over 6 months or a year without communication. [1] bit 0: was there a leap second in the most recent period, bit 1: was it positive or negative; bit 2: will there be a leap second at the end of the current period, bit 3: will it be positive or negative. Bike shed my fictious encoding if you like, but it's good enough. Use a whole 8-bits, go wild.
- aftbit 4y ago
  Cesium reference clocks can operate with accuracy around 10^-14 (aka 0.01 parts per trillion). In a year, a cesium clock would slip by a few tenths of a microsecond. That said, the whole "submerged computer must surface" thing is a bit of a red herring argument IMO. What use case would you have for needing to keep time in sync within seconds with the outside world, but being unable to communicate with that world? If you're trying to plan simultaneous delayed action across the world, it would suffice to merely be in sync with each other, leap seconds ignored.
  - fanf2 4y ago
    The chip-scale atomic clocks were developed to support precise timekeeping for small devices that can’t communicate. One example is undersea sensor networks, where you want to leave the sensors in place for a year or more, and when you return you can correlate the readings from the sensors because you know they were all ticking at the same rate the whole time.
- fanf2 4y ago
  My encoding uses about 2.5 bits per year https://dotat.at/cgi/git/leapsecs.git/blob/HEAD:/doc/spec.md https://dotat.at/cgi/git/leapsecs.git/blob/HEAD:/doc/spec.md

toast0 4y ago

> Well coordinated timekeeping across devices that may not always be able to transfer data is far, far more important. How do you have a well coordinated clock without being able to get four bits [1] per year of leap second data? It's hard to keep within one second of a time standard over 6 months or a year without communication. [1] bit 0: was there a leap second in the most recent period, bit 1: was it positive or negative; bit 2: will there be a leap second at the end of the current period, bit 3: will it be positive or negative. Bike shed my fictious encoding if you like, but it's good enough. Use a whole 8-bits, go wild.

aftbit 4y ago
Cesium reference clocks can operate with accuracy around 10^-14 (aka 0.01 parts per trillion). In a year, a cesium clock would slip by a few tenths of a microsecond. That said, the whole "submerged computer must surface" thing is a bit of a red herring argument IMO. What use case would you have for needing to keep time in sync within seconds with the outside world, but being unable to communicate with that world? If you're trying to plan simultaneous delayed action across the world, it would suffice to merely be in sync with each other, leap seconds ignored.
- fanf2 4y ago
  The chip-scale atomic clocks were developed to support precise timekeeping for small devices that can’t communicate. One example is undersea sensor networks, where you want to leave the sensors in place for a year or more, and when you return you can correlate the readings from the sensors because you know they were all ticking at the same rate the whole time.
fanf2 4y ago
My encoding uses about 2.5 bits per year https://dotat.at/cgi/git/leapsecs.git/blob/HEAD:/doc/spec.md https://dotat.at/cgi/git/leapsecs.git/blob/HEAD:/doc/spec.md