5 ms·

You have one of my favorite comments on this entire thread - so I'm interested in your thoughts on who leap seconds are useful for, if not Astronomers (and clea

You have one of my favorite comments on this entire thread - so I'm interested in your thoughts on who leap seconds are useful for, if not Astronomers (and clearly not Meta).

gmiller123456 4y ago
They are useful for ordinary people. Without them, at some point in the future people would go to work at 8am at sunset and go to bed at sunrise. Leap seconds are a way for everyone to agree to shift their schedules by 1 second to stay in sync with solar time. It's subtle enough that most people don't even know they exist, nor will it have an effect on most systems. Larger jumps would be much more difficult to ignore, and smaller jumps would be more frequent.
- jefftk 4y ago
  How long from now are you talking about? Eyeballing it, I think it would take us about a thousand years to get off by an hour?
  - balefrost 4y ago
    In the worst case, you would get 2 leap seconds per year. So in the worst case, 1800 years. However, in the past 50 years, we've only had 27. So at the current rate, probably more like 6667 years to be off by an hour. Of course, if the earth's rotation changed speed by so much that 2 leap seconds per year wasn't enough, we'd find a way to cram more in. In fact, in that case, the case for leap seconds would probably get stronger.
    - furyofantares 4y ago
      I would absolutely take the cost of work schedules being adjusted by an hour once every 6667 years over the cost of 6667 years of programmers having to deal with leap seconds and everyone else having to deal with the fallout of any bugs from that. How long has the 9-5 even existed? Less than 200 years? At no point in 6667 years would anyone notice any consequences of the drift, culture and work schedules change so much faster than that.
  - throw0101a 4y ago
    > How long from now are you talking about? Eyeballing it, I think it would take us about a thousand years to get off by an hour? The Julian calendar being off with regards to leap years wasn't a problem… until it was. And then someone had to fix it: * https://en.wikipedia.org/wiki/Gregorian_calendar https://en.wikipedia.org/wiki/Gregorian_calendar
- staticassertion 4y ago
  We change our clocks twice a year by an hour I think we could handle an hour every millenia.
  - alistairSH 4y ago
    And, by some accounts, every time we do, auto deaths and other bad things increase for some period after the change. Not to mention the weeks of bitching on either side of the change about how bad/great the time change actually is.
    - staticassertion 4y ago
      One second every thousand years.
      - jefftk 4y ago
        Do you mean one hour?
        staticassertion 4y ago
        Yeah, one hour. Whoops.
        throw0101a 4y ago
        > Yeah, one hour. Whoops. I think your comment is a precursor to what would happen if we tried to get a one-off event right…
        staticassertion 4y ago
        Right I'm sure we'll forget.
  - gmiller123456 4y ago
    The physical effort of setting a clock is not the issue. Switching to "leap hours" would involve a good part of the world living with about 9am sunrise (or a 3:30pm sunset) for hundreds of years. It'd be a really hard sell to say that's actually better. DST is adjusting to the amount of daylight available, so there's not much of a negative impact. Systems that need to be more accurate just set their time zones to UTC. And one second every year or so is far within the accuracy of a typical computer clock, so anything that needs something better is already going to have a complex time synchronization system.
- groby_b 4y ago
  The "ordinary people" really don't care about leap seconds. Like really, really not. It's less than a minute in a life span. Just skip summer time once every millenium something.
- icambron 4y ago
  This isn’t what would happen. Even we had a huge number of inexplicably needed leap seconds (there are 3600 seconds in an hour), local offsets would just change, for the same reason that people on the other side of the planet have a different time on their watch than you do. And if for some reason we proved incapable of doing that, then social conventions on when the work day started would shift relative to the local time. There just is no danger of people going to work at sunset. I’m not saying that abandoning leap seconds is a good idea, just that abandoning them wouldn’t consign future generations to whacky schedules.

You have one of my favorite comments on this entire thread - so I'm interested in your thoughts on who leap seconds are useful for, if not Astronomers (and clearly not Meta).

gmiller123456 4y ago

They are useful for ordinary people. Without them, at some point in the future people would go to work at 8am at sunset and go to bed at sunrise. Leap seconds are a way for everyone to agree to shift their schedules by 1 second to stay in sync with solar time. It's subtle enough that most people don't even know they exist, nor will it have an effect on most systems. Larger jumps would be much more difficult to ignore, and smaller jumps would be more frequent.

jefftk 4y ago
How long from now are you talking about? Eyeballing it, I think it would take us about a thousand years to get off by an hour?
- balefrost 4y ago
  In the worst case, you would get 2 leap seconds per year. So in the worst case, 1800 years. However, in the past 50 years, we've only had 27. So at the current rate, probably more like 6667 years to be off by an hour. Of course, if the earth's rotation changed speed by so much that 2 leap seconds per year wasn't enough, we'd find a way to cram more in. In fact, in that case, the case for leap seconds would probably get stronger.
  - furyofantares 4y ago
    I would absolutely take the cost of work schedules being adjusted by an hour once every 6667 years over the cost of 6667 years of programmers having to deal with leap seconds and everyone else having to deal with the fallout of any bugs from that. How long has the 9-5 even existed? Less than 200 years? At no point in 6667 years would anyone notice any consequences of the drift, culture and work schedules change so much faster than that.
- throw0101a 4y ago
  > How long from now are you talking about? Eyeballing it, I think it would take us about a thousand years to get off by an hour? The Julian calendar being off with regards to leap years wasn't a problem… until it was. And then someone had to fix it: * https://en.wikipedia.org/wiki/Gregorian_calendar https://en.wikipedia.org/wiki/Gregorian_calendar
staticassertion 4y ago
We change our clocks twice a year by an hour I think we could handle an hour every millenia.
- alistairSH 4y ago
  And, by some accounts, every time we do, auto deaths and other bad things increase for some period after the change. Not to mention the weeks of bitching on either side of the change about how bad/great the time change actually is.
  - staticassertion 4y ago
    One second every thousand years.
    - jefftk 4y ago
      Do you mean one hour?
      - staticassertion 4y ago
        Yeah, one hour. Whoops.
        throw0101a 4y ago
        > Yeah, one hour. Whoops. I think your comment is a precursor to what would happen if we tried to get a one-off event right…
        staticassertion 4y ago
        Right I'm sure we'll forget.
- gmiller123456 4y ago
  The physical effort of setting a clock is not the issue. Switching to "leap hours" would involve a good part of the world living with about 9am sunrise (or a 3:30pm sunset) for hundreds of years. It'd be a really hard sell to say that's actually better. DST is adjusting to the amount of daylight available, so there's not much of a negative impact. Systems that need to be more accurate just set their time zones to UTC. And one second every year or so is far within the accuracy of a typical computer clock, so anything that needs something better is already going to have a complex time synchronization system.
groby_b 4y ago
The "ordinary people" really don't care about leap seconds. Like really, really not. It's less than a minute in a life span. Just skip summer time once every millenium something.
icambron 4y ago
This isn’t what would happen. Even we had a huge number of inexplicably needed leap seconds (there are 3600 seconds in an hour), local offsets would just change, for the same reason that people on the other side of the planet have a different time on their watch than you do. And if for some reason we proved incapable of doing that, then social conventions on when the work day started would shift relative to the local time. There just is no danger of people going to work at sunset. I’m not saying that abandoning leap seconds is a good idea, just that abandoning them wouldn’t consign future generations to whacky schedules.