If you don’t understand it, you must not work with a lot of humans doing human things. Ask a bunch of friends that don’t work with computers what today, plus one year is. You’ll hear everything from “365 days” to today’s date next year to 365.25 days. At no point do you hear the current time, on this date.
So if lots of things go wrong that you are having to rotate this in a year, you are doomed to fail because there’s also a time stamp on it. There’s no grace period, so things will break.
If there’s a revocation system, there’s no reason for a hard expiration of the token is still being used.
> If it were "one year and one day" you'd have the same exact problem.
No, it would not, at all. Think of it like this: if I ask you to put something on your calendar one year from now, what kind of calendar event would it be? It would probably be an "all day event" and you wouldn't even to think to ask "what time?"
> Revocation and expiration are virtually the same thing.
Revocation is an intentional act done by humans. Expiration happens simply by the passage of time in relation to the movement of Earth around the sun.