Rails 6.2 should use timestampz as the default Postgres field type for datetime and timestamp.
timestamp without zone (current default)
can be converted to whatever timezone as appropriate. e.g.
(('2016-06-03 15:06:35'::timestamp AT TIME ZONE 'UTC') AT TIME ZONE 'America/Chicago') type of casting.
timestamp with zone (timestampz) is like
which includes the zone
+00, and is stored as an offset from the epoch as opposed to without any context. I can’t see why this would be at all problematic unless perhaps you’re working with systems which can’t handle that