Unix Time and a Modest Proposal • Hacker News Board

Re: Unix Time and a Modest Proposal

#41

Post by quantified » Fri, Dec 27, 2024, 8:34 PM UTC

paxys wrote: post #24

3eb7988a1663 wrote: post #3

The ratio is around 365.2422. Calling it 365 is too crude. Julius Caesar said we should call it 365 1/4, and that was good enough for a while. This is blowing my mind that thousands of years ago they were able to measure the orbits to this level of accuracy.

Internet "influencers" really have us convinced that humans were barbaric apes until a century or two ago and then suddenly invented the modern world. What about all the achievements before then? Could we not have used math and science a few thousand years ago? Nope, it was all aliens of course.

It's only internet influencers if you grew up in the last few years and get most of your world information from them. I'm sure that's more than a roomful of people. Anthropologists have been doing it for well over a hundred years.

Re: Unix Time and a Modest Proposal

#42

Post by amluto » Fri, Dec 27, 2024, 9:58 PM UTC

yuliyp wrote: post #38

amluto wrote: post #34

Earlier quoted context omitted.

The tricky part seems like it would be that one needs precision quite a bit better than one day. So either the measurement can be done over the course of many years or the time of the solstice needs to be determined to excellent precision.

It requires someone to at some point remember that "Hey when I was a kid 20 years ago the solstice was on December 22 but now it's on December 17, what happened?" and then go looking at historical records to generate a trend line with a slope of 0.25 days / year. The measurement doesn't have to be at one point.

Sure, but it needs an extra digit or two do do as well as the Gregorian calendar. Doable, but longer records are needed.

Re: Unix Time and a Modest Proposal

#43

Post by yuliyp » Fri, Dec 27, 2024, 10:54 PM UTC

amluto wrote: post #42

yuliyp wrote: post #38

Earlier quoted context omitted.

It requires someone to at some point remember that "Hey when I was a kid 20 years ago the solstice was on December 22 but now it's on December 17, what happened?" and then go looking at historical records to generate a trend line with a slope of 0.25 days / year. The measurement doesn't have to be at one point.

Sure, but it needs an extra digit or two do do as well as the Gregorian calendar. Doable, but longer records are needed.

The adjustment to 365.25 came during Roman times. The Gregorian adjustment came after well over a thousand years to realize the drift since Julius Caesar's time.