5 ms·

Do you honestly consider modifying the core idea of the 24 hour day to be a "slight tweak"? I can't even imagine how many different things rely on that assumpti

Do you honestly consider modifying the core idea of the 24 hour day to be a "slight tweak"? I can't even imagine how many different things rely on that assumption. (and I'm sorry, but what does "naming months and seasons in Mars" have to do with this?)

cornholio 4y ago
> and I'm sorry, but what does "naming months and seasons in Mars" have to do with this? Time of day and calendaring and discussed together because they allow you to ask things like "what was the date and time on Mars prime meridian on Feb 2 2023 6:00 UTC" and get a recognizable date and time back. It's essentially a timezone, albeit a very strange one with a variable offset. > modifying the core idea of the 24 hour day to be a "slight tweak"? Ok, maybe an exaggerated hand-wave on my part. It's a slight software tweak on my desk clock. I was contrasting with the alternative of modifying a fundamental SI unit and more or less rebuilding from scratch all hardware sent on Mars. The fuckups alone resulting from confusing Earth seconds with Mars seconds.
wongarsu 4y ago
You have basically three options for timekeeping on mars: adjust the day, adjust the second, or give up on days syncing with the (apparent) movement of the sun. The first option breaks mostly assumptions made in software and processes, the second mostly assumptions made in hardware, and the third breaks human's circadian rythm (a 23 or 25 hour rythm isn't a big deal, but it has to sync to light). Of those three, the things that rely on 24 hour days seem to be the easiest to change. Though there is precedent both to messing with the length of a day (a leap second makes the day one second longer, making 23:59:60 a valid time) and the length of a second (google pretends like seconds are slightly longer as an alternative way to deal with leap seconds)
- claviola 4y ago
  I must have missed something. This article is about the Moon.
  - KptMarchewa 4y ago
    And comment you replied to is about Mars.
    - jefftk 4y ago
      But it's not clear why that author decided to talk about Mars. They didn't connect their comment to to the article at all.
      - cornholio 4y ago
        Sorry about that, I was just throwing somewhere at the bottom of the comment section an off-topic ideea I've been toying with. Didn't expect it will raise such interest and be voted towards the top.
        thefifthsetpin 4y ago
        No need to apologize. We knew what we were doing when upvoting a comment by the great cornholio.
yrro 4y ago
The very first entry on the list of falsehoods programmers believe about time[0] is that there are always 24 hours in a day. [0] https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b... 23:59:60 happens when we add leap seconds to the clock, for instance...
- claviola 4y ago
  I wasn't talking about software development by itself, but human behaviour.
  - ceejayoz 4y ago
    Human behavior will largely just appreciate the extra half hour of sleep each day. Round-the-clock shiftwork (hospitals, power plants, etc.) will require minor tweaking; your eight hour shift probably just becomes 8:10 or so. (It's worse for humans on Earth working Mars time, which is a thing that already happens. They come in 40 mins later every day. https://mars.nasa.gov/resources/20090/living-on-mars-time/ https://mars.nasa.gov/resources/20090/living-on-mars-time/)
- jefftk 4y ago
  > there are always 24 hours in a day Daylight savings time is a much larger departure from this rule ;) > 23:59:60 happens when we add leap seconds to the clock Not anymore! Or, maybe not anymore. We've agreed to phase out leap seconds before 2035 [1] and we probably won't get a 23:59:60 before then [2]. [1] https://www.nature.com/articles/d41586-022-03783-5 https://www.nature.com/articles/d41586-022-03783-5 [2] https://manifold.markets/Yev/will-there-be-another-positive-leap https://manifold.markets/Yev/will-there-be-another-positive-...
  - yrro 4y ago
    Oh, I didn't realise that this proposal had been adopted! I read[0] that "It will take about 50,000 years for a mean solar day to lengthen by one second (at a rate of 2 ms per century)" and "The [accumulated] difference between UTC and UT would reach 0.5 hours after the year 2600 and 6.5 hours around 4600" which I expect will be sufficient to take us through to the time where we will no longer need co-ordinated time or an IERS. [0] https://en.wikipedia.org/wiki/Coordinated_Universal_Time https://en.wikipedia.org/wiki/Coordinated_Universal_Time
skissane 4y ago
For software that runs on Mars, I think "Mars date/time" has to be a brand new set of APIs and data types. The existing date/time APIs/types are for Earth times only. The "local time zone" on Mars would just be UTC. That way there wouldn't be much possibility of bugs based on confusing Earth and Mars time scales – all pre-existing software would still work with Earth date/times, and anything that needed to deal with Mars date/times specifically would have to be modified to handle them.
- RedNifre 4y ago
  No, Mars has less mass than Earth, so if you use Earth UTC, Mars seconds will be longer than SI seconds, which does not seem like a good idea.
  - skissane 4y ago
    I think you misunderstood my point - I was saying make both Earth UTC and some Martian time scale available, just use a new API and data types for the latter. Which one to use in any given use case will be up to the application developer.
manojlds 4y ago
cough leap second cough
- claviola 4y ago
  Sure, the leap second is a thing. We still represent the day as 24 hours for humans. They didn't seem to be talking about an "under the hood" hand waving of a significant part of the day.
jjk166 4y ago
Way easier than changing the rotation speed of mars.

cornholio 4y ago

> and I'm sorry, but what does "naming months and seasons in Mars" have to do with this? Time of day and calendaring and discussed together because they allow you to ask things like "what was the date and time on Mars prime meridian on Feb 2 2023 6:00 UTC" and get a recognizable date and time back. It's essentially a timezone, albeit a very strange one with a variable offset. > modifying the core idea of the 24 hour day to be a "slight tweak"? Ok, maybe an exaggerated hand-wave on my part. It's a slight software tweak on my desk clock. I was contrasting with the alternative of modifying a fundamental SI unit and more or less rebuilding from scratch all hardware sent on Mars. The fuckups alone resulting from confusing Earth seconds with Mars seconds.

wongarsu 4y ago

You have basically three options for timekeeping on mars: adjust the day, adjust the second, or give up on days syncing with the (apparent) movement of the sun. The first option breaks mostly assumptions made in software and processes, the second mostly assumptions made in hardware, and the third breaks human's circadian rythm (a 23 or 25 hour rythm isn't a big deal, but it has to sync to light). Of those three, the things that rely on 24 hour days seem to be the easiest to change. Though there is precedent both to messing with the length of a day (a leap second makes the day one second longer, making 23:59:60 a valid time) and the length of a second (google pretends like seconds are slightly longer as an alternative way to deal with leap seconds)

claviola 4y ago
I must have missed something. This article is about the Moon.
- KptMarchewa 4y ago
  And comment you replied to is about Mars.
  - jefftk 4y ago
    But it's not clear why that author decided to talk about Mars. They didn't connect their comment to to the article at all.
    - cornholio 4y ago
      Sorry about that, I was just throwing somewhere at the bottom of the comment section an off-topic ideea I've been toying with. Didn't expect it will raise such interest and be voted towards the top.
      - thefifthsetpin 4y ago
        No need to apologize. We knew what we were doing when upvoting a comment by the great cornholio.

yrro 4y ago

The very first entry on the list of falsehoods programmers believe about time[0] is that there are always 24 hours in a day. [0] https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b... 23:59:60 happens when we add leap seconds to the clock, for instance...

claviola 4y ago
I wasn't talking about software development by itself, but human behaviour.
- ceejayoz 4y ago
  Human behavior will largely just appreciate the extra half hour of sleep each day. Round-the-clock shiftwork (hospitals, power plants, etc.) will require minor tweaking; your eight hour shift probably just becomes 8:10 or so. (It's worse for humans on Earth working Mars time, which is a thing that already happens. They come in 40 mins later every day. https://mars.nasa.gov/resources/20090/living-on-mars-time/ https://mars.nasa.gov/resources/20090/living-on-mars-time/)
jefftk 4y ago
> there are always 24 hours in a day Daylight savings time is a much larger departure from this rule ;) > 23:59:60 happens when we add leap seconds to the clock Not anymore! Or, maybe not anymore. We've agreed to phase out leap seconds before 2035 [1] and we probably won't get a 23:59:60 before then [2]. [1] https://www.nature.com/articles/d41586-022-03783-5 https://www.nature.com/articles/d41586-022-03783-5 [2] https://manifold.markets/Yev/will-there-be-another-positive-leap https://manifold.markets/Yev/will-there-be-another-positive-...
- yrro 4y ago
  Oh, I didn't realise that this proposal had been adopted! I read[0] that "It will take about 50,000 years for a mean solar day to lengthen by one second (at a rate of 2 ms per century)" and "The [accumulated] difference between UTC and UT would reach 0.5 hours after the year 2600 and 6.5 hours around 4600" which I expect will be sufficient to take us through to the time where we will no longer need co-ordinated time or an IERS. [0] https://en.wikipedia.org/wiki/Coordinated_Universal_Time https://en.wikipedia.org/wiki/Coordinated_Universal_Time

skissane 4y ago

For software that runs on Mars, I think "Mars date/time" has to be a brand new set of APIs and data types. The existing date/time APIs/types are for Earth times only. The "local time zone" on Mars would just be UTC. That way there wouldn't be much possibility of bugs based on confusing Earth and Mars time scales – all pre-existing software would still work with Earth date/times, and anything that needed to deal with Mars date/times specifically would have to be modified to handle them.

RedNifre 4y ago
No, Mars has less mass than Earth, so if you use Earth UTC, Mars seconds will be longer than SI seconds, which does not seem like a good idea.
- skissane 4y ago
  I think you misunderstood my point - I was saying make both Earth UTC and some Martian time scale available, just use a new API and data types for the latter. Which one to use in any given use case will be up to the application developer.

manojlds 4y ago

cough leap second cough

claviola 4y ago
Sure, the leap second is a thing. We still represent the day as 24 hours for humans. They didn't seem to be talking about an "under the hood" hand waving of a significant part of the day.

jjk166 4y ago

Way easier than changing the rotation speed of mars.