Also to not use the TIMESTMAP type in general, which is full of similar by-default footguns (off the top of my head: default 1-second precision, connection-local timezone autoconversion). At least for non-historic events.

Use uint64 as nanoseconds from epoch. Explicitly convert to/from UTC in your application code. Smear your leap seconds. This will last you until 2554, by which time I hope computers as we know are dead. Bonus: these make for decent strong-read-ordered internal UUIDs, given good retry logic.