Postgres & Django - DataError: time zone not recognized - django

Question

We are getting the following error from some of our users:
DataError: time zone "Asia/Qostanay" not recognized
We've found out that the problem was coming from the following SQL query:
SELECT *
FROM "app_foobar"
WHERE (
EXTRACT('hour' FROM "app_foobar"."date" AT TIME ZONE 'Asia/Qostanay') = 0
);

Answer 1

There are two problems:
Timezone definitions change over time. Update Ubuntu timezone data:
sudo apt-get update
sudo apt-get install tzdata
Postgres 11.1 doesn't support this timezone (and some others). Update Postgres to 11.4:
sudo apt-get update
sudo apt-get install postgresql-11
sudo apt-get install postgresql-client-11
Some notes on updating Postgres:
No data migration needed for minor versions (e.g. 11.0 -> 11.4). Only executables are updated.
PostgreSQL will restart (database will be unavailable for a second or two)
The relevant postgresql changelog (https://www.postgresql.org/docs/release/11.2/):
Update time zone data files to tzdata release 2018i for DST law changes in Kazakhstan, Metlakatla, and Sao Tome and Principe. Kazakhstan's Qyzylorda zone is split in two, creating a new zone Asia/Qostanay, as some areas did not change UTC offset. Historical corrections for Hong Kong and numerous Pacific islands.