In cases where the data itself doesn't carry the unit (or TZ in this case), I usually ask that the unit-less columns at least include the unit in the name. A TZ-less column is not that bad if it is suffixed "UTC", e.g. `ExecutionTimeUtc`.

There are probably real world cases where dropping the TZ/offset provides meaningful performance/storage savings, but it hasn't been the typical case in my current sector.

> Every user has to guess, or be informed, that they’re UTC.

At least they are UTC and not EST or PST...

They must yearn for the before times when text could be in an encoding specified only as: "your guess is as good mine!"