SQLSTATE 22023Severity lowLab verified

Incident brief

date_trunc invalid field

date_trunc() was called with a field name it doesn't recognize. PostgreSQL rejected the call instead of guessing what precision was meant.

Reproduced on PostgreSQL 16.14Verified 2026-07-16 (Docker lab, PostgreSQL 16.14)Reviewed by Verified against PostgreSQL 16.14 in an isolated lab environment

In 10 seconds

What: date_trunc invalid field
What triggers it: Call date_trunc() with a field name that isn't in its accepted list, e.g. 'fortnight'.
The fix: Use one of date_trunc()'s accepted field names instead: microseconds, milliseconds, second, minute, hour, day, week, month, quarter, year, decade, century, or millennium.
Proof: Reproduced on PostgreSQL 16.14 → date_trunc('fortnight', <timestamp>) was rejected with SQLSTATE 22023, because 'fortnight' is not one of date_trunc's accepted field names.

The fix

What to do right now

The immediate, application-level response to this error.

Use one of date_trunc()'s accepted field names instead: microseconds, milliseconds, second, minute, hour, day, week, month, quarter, year, decade, century, or millennium.
Don't assume a field name that works with EXTRACT() also works with date_trunc() — see the premium counterexample for 'dow'.

Fix — SQL

SELECT date_trunc('week', TIMESTAMP '2024-03-15 14:30:00');

Diagnose

See it live on the server

Run these against the affected instance to confirm the diagnosis before you act.

Standard triage — not specific to this error

These are canonical PostgreSQL system-catalog queries, shown as SQL to run. No sample output is attached because this is general triage, not a captured lab transcript.

This SQLSTATE does not have an error-specific live snapshot yet. These are the canonical system-catalog queries you run against the affected server to see the problem in real time — standard triage, not a reproduced transcript.

What is running right now

Active backends, how long each has been running, and what it is waiting on.

SELECT pid,
       state,
       wait_event_type,
       wait_event,
       now() - query_start AS running_for,
       left(query, 80)     AS query
FROM   pg_stat_activity
WHERE  state <> 'idle'
  AND  pid <> pg_backend_pid()
ORDER  BY running_for DESC NULLS LAST;

Who is blocking whom

Turn raw blocking PIDs into the actual queries on both sides of the wait.

SELECT blocked.pid    AS blocked_pid,
       blocked.query  AS blocked_query,
       blocking.pid   AS blocking_pid,
       blocking.query AS blocking_query
FROM   pg_stat_activity AS blocked
JOIN   LATERAL unnest(pg_blocking_pids(blocked.pid)) AS b(pid) ON true
JOIN   pg_stat_activity AS blocking ON blocking.pid = b.pid
WHERE  cardinality(pg_blocking_pids(blocked.pid)) > 0;

Locks that are still waiting

Every lock a backend has requested but not yet been granted.

SELECT l.pid,
       l.locktype,
       l.mode,
       l.granted,
       COALESCE(c.relname, l.transactionid::text) AS object
FROM   pg_locks l
LEFT   JOIN pg_class c ON c.oid = l.relation
WHERE  NOT l.granted
ORDER  BY l.pid;

Reproduce & verify

A real, single-session PostgreSQL reproduction

A literal transcript of SQL run against a live PostgreSQL instance in an isolated lab — the commands below are exactly what was executed.

1Call date_trunc() with a field name that isn't in its accepted list, e.g. 'fortnight'.
2SQLSTATE 22023 is reported; no value is returned.

One client: date_trunc() called with an unrecognized field name against a fixed literal timestamp.

Schema setup

-- No table needed: the failure happens purely inside date_trunc()'s field argument.
SELECT 'no schema required' AS setup_note;

The unrecognized field name

SELECT date_trunc('fortnight', TIMESTAMP '2024-03-15 14:30:00');

Confirming the session still works

SELECT 1 AS session_still_alive;

What PostgreSQL actually returned

Schema setup output

     setup_note     
--------------------
 no schema required
(1 row)

The unrecognized field name output

ERROR:  unit "fortnight" not recognized for type timestamp without time zone

Confirming the session still works output

 session_still_alive 
---------------------
                   1
(1 row)

Related & next steps

Follow the thread

Everything this error touches — jump straight to the sibling error, term, runbook, or parameter.

Verification

PG 16.14

Last verified: 2026-07-16 (Docker lab, PostgreSQL 16.14)
Reviewed by: Verified against PostgreSQL 16.14 in an isolated lab environment
Audit status: reviewed