Except that’s not entirely the story of time zones. They’re political divisions. Some of them match up with the sun better than others. For instance, the sunset time gets pretty weird in LV over the winter.
Which I think is perfectly fine (if not necessary) for that layer. The human body doesn't care for extra seconds, and science doesn't either. So who do we do the "coordination" in UTC for? If - over hundreds of years - the time zone drifts off into weirdness, it can be changed politically. What more do you need?
Oh. In UT1 there number of seconds in a day is constant, so it's value is defined by the rotation of the earth which is slowing. UTC is better than UT1 in that regard. Maybe UT1 is fine for humans, but really humans just assume ut1.
UTC adds little of value on top of TAI, except some headache for clock synchronization. So I argue for basing timezones directly on TAI, as I see TAI as the least impractical reference.
Which I think is perfectly fine (if not necessary) for that layer. The human body doesn't care for extra seconds, and science doesn't either. So who do we do the "coordination" in UTC for? If - over hundreds of years - the time zone drifts off into weirdness, it can be changed politically. What more do you need?