Comment by WorldMaker

Keeping a UTC offset is two extra bytes and with a UTC offset you can do all of your time comparisons and time math as if everything was in UTC, but you have extra debugging information in the UTC offset. It's still sometimes useful to store a time zone as offsets to timezones certainly are not 1:1 (esp. with DST math), but some places like logs and past dates UTC offset is sufficient and you don't even need to store timezone.

Postgres doesn't a native type that supports UTC offsets, but some other databases do and it is extremely useful. At this point in my career, I would never choose UTC storage over UTC Offset storage.