They are not required when using TAI. The only sensible way to count time is with TAI. UTC and its leap seconds should only be used for display/parsing, not for counting time. That people do otherwise is rage inducing.

A time expressed in TAI that is in the future has no conversion to human-readable time. That is not a very useful piece of data for many, many use cases.

> TAI that is in the future has no conversion to human-readable time

Doesn't it convert to within some margin for error? Checking Wikipedia, I see that the delta between TAI and Unix time has only drifted 27 seconds since 1972. That should be more than sufficient for your average mundane human readable purpose.

YEP! no timestamp should EVER be in UTC.

What's the problem with slowly drifting away from solar time? If 9:00am became 9:10am by the time I'm 100 years old I don't think I'd encounter any difficulties. Who requires this level of accuracy?

Because then you'd still need an almanac of the drift in determining celestial location/navigation.

It's easier to just keep high noon at the Greenwich observatory as the defining datum, since most worldwide coordinates ultimately reference back to it, being 0deg longitude.

Ultimately, either time or location would need to be adjusted, and it's easier to do time. Plus it's consistent with what's been done historically.

It’s sorta like asking why we don’t fix pi at 3.1, even if the scale may (initially) be smaller. Or get rid of time zones: It’s sacrificing truth for the convenience of about a dozen people in IT.

>It’s sacrificing truth for the convenience of about a dozen people in IT.

And this kind of thing can never be undone. See: NTSC "60" Hz actually being 59.94 Hz due to the transition between black and white and color TV. Monitors today still have this lasting effect for consistency's sake.

> It’s sacrificing truth for the convenience of about a dozen people in IT.

But those dozen IT people think the trade off is really worth it (for them)!

This is exactly the kind of thing that is often done. Some software will just treat all months as having 30 days because it simplifies logic massively and doesn't cause that much of an issue.

There isn't a huge problem with changing it, there are people who want to do exactly that and do something else instead. The prominent alternatives that I know of still do something to keep time tied to the mean solar day, though, and changing time standards can be a complicated process so it's likely to take a while.

https://en.wikipedia.org/wiki/Leap_second#International_prop...