Same with leap days though?
The point is that it's weird that we handle a day every 4 years off in a different way to a couple of second being off.
Same with leap days though?
The point is that it's weird that we handle a day every 4 years off in a different way to a couple of second being off.
Don't we handle them mostly the same? In a leap year, the month of February gets a 29th day, labeled 29. On a leap second, one of the minutes gets a 61st second, labeled 60. Or we drop the 60th second, and second 58 is followed by second 00 of the next minute.
The notable differences are that
1) the leap second happens at the same time globally (23:59:60 UTC), while leap days start at 00:00 local time
2) leap seconds happen at irregular intervals
3) leap seconds are nearly universally implemented wrong, because the ability to show :60 on a second display for for one second at most twice per year is just not worth the implementation complexity
You could argue about 1, but the alternative would lead to much more complicated timezone math (time zones can be an additional one second apart from each other depending on whether the leap second is already applied) for very limited benefit. Number 2 seems unavoidable, and 3 is entirely unintended, just the way things have worked out in real life
The leap day system handles the mean, the leap seconds handle the variance around the mean. The need for leap seconds is not predictable—they zero out accumulated error.
No, they handle totally different things. Leap seconds handle the earth spinning at a varying speed. They would be a problem even if the sun didn't exist. Leap years handle the fact that earth spins don't evenly divide orbits around the sun. They would be a problem even if clocks didn't exist.
We can imagine a system where leap days are split into mean and variance: This would look like a council coming together every thousand years to decide if that year will have a leap day or not, but otherwise we follow the pattern.
We can also imagine a system where leap seconds are split into mean and variance: Many years from now when the Earth is notably slower, there's a guaranteed leap second every odd month, and sometimes there's an extra leap second in June.
Leap days are predictable whereas leap seconds are not.