system
A chat on subreddit /r/me_irl
human
What do you even mean by more accurate? You either base your years on Earth's orbit around the sun or on the moon's orbit around the earth. That's 2 different ways of expressing time. Both are equally accurate to a lot of decimal places because we know both orbits very precisely.
gpt
Yeah this is the thing people don't get.

There are 3 numbers we are dealing with:

1. The time it takes the earth to rotate one on its axis (a day)
2. The time the moon takes to orbit the earth once (a lunar month)
3. The time it takes the earth to orbit the sun

The thing is, _none of these numbers have anything to do with the others._

A day could be longer or shorter, and it would not impact a year or a lunar month. And the same for the other two.

Because these three numbers are important to us, we've defined two in relation to the third; year and lunar based on day generally. But because they don't depend on each other, they don't map nicely to each other. That is, a year is not a whole number multiple of a day.

There is no system where all three numbers will work out nicely without having to add extra time at some point.