I'd like to add (or rather subtract) a number of days from a timestamp.
For example from
2020-04-13 00:00:00 Europe/Berlin I want to subtract 20 days and I expect the result to be
2020-03-24 00:00:00 Europe/Berlin.
If I run
select ('2020-04-13 00:00:00 Europe/Berlin'::timestamptz - INTERVAL '20 DAY') AT TIME ZONE 'Europe/Berlin'
That seems to be because PostgreSQL subtracts 20 * 24 hours (a DST switch happens during that date range) which is different from subtracting 20 days.