4 ms·

Woudln't it be easier to just "let it ride" and the next time a leap second is due, just not add it?

throwaway894345 6y ago
It's interesting to think about the ramifications of decoupling our measurement of time from the earth's position in the solar system. For example, when we read that something happened around 11 AM, we know that it's probably daylight time, but if we allow for drift, then we can't make that assumption anymore for certain timescales. If the error is small, we can probably deal with it the same way most people understand that dollars in 1950 don't have the same value as dollars today.
- Archelaos 6y ago
  GPS time is like this. See: https://en.wikipedia.org/wiki/Global_Positioning_System#Timekeeping https://en.wikipedia.org/wiki/Global_Positioning_System#Time...
- wcoenen 6y ago
  Note that we don't sync to the Earth's position in the solar system (sidereal year), but to the seasons (tropical year).
- myself248 6y ago
  Unless you're within a few feet of the longitude of the center of the timezone, this is already the case. That ship sailed, back in the railroad era when we decided to standardize time away from mean solar time. If we assume that the Gregorian calendar remains in use for as long as it's already been in use, the total accumulated error would likely be on the order of minutes. We could use a monotonic time scale like TAI for literally centuries and nobody would notice except astronomers, and arguably it would simplify astronomical corrections too because the underlying scale would be monotonic, which it isn't presently.
  - klodolph 6y ago
    > That ship sailed, back in the railroad era when we decided to standardize time away from mean solar time. I’ll make the case here that we still use mean solar time, we just quantize it and push it around for political reasons. In any case, using time zones just means that your clock is off by maybe a half hour or 45 minutes in the lower US, and given the natural variation for sunrise and sunset, that doesn’t seem like an outrageous amount of error for temperate latitudes. Granted, there are a few places in the world with larger differences, like Spain or western China, or Argentina for some reason. Changes in the period of the Earth’s rotation have been estimated based on records of eclipses from as far back as the 8th century, which show that the Earth’s rotational speed is slowing down. Trying to extrapolate from fifty years of atomic time is going to give you the “on the order of minutes” estimate which is likely wrong. If you are trying to work out the error over five centuries, you should probably be using the best available data, which is records of eclipses and ephemerides.
    - kevin_thibedeau 6y ago
      It's more than 45 minutes on the western extremes in the EST, CST, and MST zones.
      - klodolph 6y ago
        I chose the wording “maybe a half hour or 45 minutes” to make it crystal-clear that the exact number was not relevant to the argument, in a vain effort to avoid responses like this one. Perhaps I should be more explicitly vague in the future. HN is tiring.
        danaliv 6y ago
        No, you’re absolutely right. As someone who uses UTC professionally in aerospace ops, trust me when I say your clock is still definitely tied to solar time even if it’s “off” by whatever. Try using UTC exclusively—I don’t just mean on your servers, I mean in every single aspect of your life—and you’ll see what I mean.
      - deleted 6y ago
- zokier 6y ago
  You are assuming that timezones wouldn't change if the difference would be great enough to notice, something that I don't see any reason to assume.
anigbrowl 6y ago
Suppose for argument's sake that this year produces shorter days, and the trend continues.

It's interesting to think about the ramifications of decoupling our measurement of time from the earth's position in the solar system. For example, when we read that something happened around 11 AM, we know that it's probably daylight time, but if we allow for drift, then we can't make that assumption anymore for certain timescales. If the error is small, we can probably deal with it the same way most people understand that dollars in 1950 don't have the same value as dollars today.

Archelaos 6y ago
GPS time is like this. See: https://en.wikipedia.org/wiki/Global_Positioning_System#Timekeeping https://en.wikipedia.org/wiki/Global_Positioning_System#Time...
wcoenen 6y ago
Note that we don't sync to the Earth's position in the solar system (sidereal year), but to the seasons (tropical year).
myself248 6y ago
Unless you're within a few feet of the longitude of the center of the timezone, this is already the case. That ship sailed, back in the railroad era when we decided to standardize time away from mean solar time. If we assume that the Gregorian calendar remains in use for as long as it's already been in use, the total accumulated error would likely be on the order of minutes. We could use a monotonic time scale like TAI for literally centuries and nobody would notice except astronomers, and arguably it would simplify astronomical corrections too because the underlying scale would be monotonic, which it isn't presently.
- klodolph 6y ago
  > That ship sailed, back in the railroad era when we decided to standardize time away from mean solar time. I’ll make the case here that we still use mean solar time, we just quantize it and push it around for political reasons. In any case, using time zones just means that your clock is off by maybe a half hour or 45 minutes in the lower US, and given the natural variation for sunrise and sunset, that doesn’t seem like an outrageous amount of error for temperate latitudes. Granted, there are a few places in the world with larger differences, like Spain or western China, or Argentina for some reason. Changes in the period of the Earth’s rotation have been estimated based on records of eclipses from as far back as the 8th century, which show that the Earth’s rotational speed is slowing down. Trying to extrapolate from fifty years of atomic time is going to give you the “on the order of minutes” estimate which is likely wrong. If you are trying to work out the error over five centuries, you should probably be using the best available data, which is records of eclipses and ephemerides.
  - kevin_thibedeau 6y ago
    It's more than 45 minutes on the western extremes in the EST, CST, and MST zones.
    - klodolph 6y ago
      I chose the wording “maybe a half hour or 45 minutes” to make it crystal-clear that the exact number was not relevant to the argument, in a vain effort to avoid responses like this one. Perhaps I should be more explicitly vague in the future. HN is tiring.
      - danaliv 6y ago
        No, you’re absolutely right. As someone who uses UTC professionally in aerospace ops, trust me when I say your clock is still definitely tied to solar time even if it’s “off” by whatever. Try using UTC exclusively—I don’t just mean on your servers, I mean in every single aspect of your life—and you’ll see what I mean.
    - deleted 6y ago
zokier 6y ago
You are assuming that timezones wouldn't change if the difference would be great enough to notice, something that I don't see any reason to assume.

anigbrowl 6y ago

Suppose for argument's sake that this year produces shorter days, and the trend continues.