I noticed that `SET TIME ZONE` / `SET timezone TO` don't work with abbreviations:
Is it a bug or this behavior is intentional (something to do with SQL standard, perhaps)?
Well, given that the limitation is documented I’d have to say it is intentional:
You cannot set the configuration parameters TimeZone or log_timezone to a time zone abbreviation, but you can use abbreviations in date/time input values and with the AT TIME ZONE operator.