ORA-01882: timezone region not found — Causes, Fixes, and Prevention
ORA-01882 is thrown by Oracle Database when it cannot resolve a specified timezone region name against its internal timezone file (timezone.dat). This typically happens after OS upgrades, Oracle migrations, or when an application passes an unrecognized timezone string to a session. Because it blocks session initialization, it can cause widespread application outages if not addressed quickly.
Top 3 Causes
1. OS Timezone Not Recognized by Oracle
Oracle maintains its own timezone registry, independent of the OS. When the OS TZ variable uses an abbreviation or format Oracle doesn't support (e.g., ROK, KST-9), ORA-01882 is raised at startup or login.
-- Check what Oracle recognizes as the DB timezone
SELECT DBTIMEZONE FROM DUAL;
-- Check current session timezone
SELECT SESSIONTIMEZONE FROM DUAL;
-- List all Oracle-supported timezone regions
SELECT TZNAME, TZABBREV
FROM V$TIMEZONE_NAMES
WHERE TZNAME LIKE 'Asia%'
ORDER BY TZNAME;
-- Verify a specific timezone exists in Oracle
SELECT COUNT(*)
FROM V$TIMEZONE_NAMES
WHERE TZNAME = 'Asia/Seoul';
Fix: Set the session timezone using an offset or a verified region name:
-- Safe fix using UTC offset (no region name dependency)
ALTER SESSION SET TIME_ZONE = '+09:00';
-- Fix using verified region name
ALTER SESSION SET TIME_ZONE = 'Asia/Seoul';
2. Outdated or Corrupted Oracle Timezone File (DST File)
Oracle ships timezone data separately from the RDBMS binary. When the DST file version is too old to include a recently added region, or the file gets corrupted during a patch, Oracle cannot locate the region name and raises ORA-01882.
-- Check the current timezone file version
SELECT * FROM V$TIMEZONE_FILE;
-- Check database-level timezone properties
SELECT PROPERTY_NAME, PROPERTY_VALUE
FROM DATABASE_PROPERTIES
WHERE PROPERTY_NAME LIKE '%TIMEZONE%';
-- Prepare for DST upgrade (check impact first)
EXEC DBMS_DST.BEGIN_PREPARE(new_version => 32);
-- Check affected tables before upgrading
SELECT * FROM SYS.DST$AFFECTED_TABLES;
-- Apply the timezone file upgrade
EXEC DBMS_DST.BEGIN_UPGRADE(parallel => 4);
EXEC DBMS_DST.UPGRADE_DATABASE(parallel => 4);
EXEC DBMS_DST.END_UPGRADE;
Download the latest timezone patch from My Oracle Support and apply it via OPatch before running the above DBMS_DST steps.
3. Invalid Timezone String Passed by Application or Session
A typo in ALTER SESSION SET TIME_ZONE, a JDBC connection property, or an application config file can directly trigger ORA-01882. Oracle performs a strict lookup — even minor case inconsistencies or outdated abbreviations will fail.
-- Validate the timezone string before using it
SELECT TZNAME
FROM V$TIMEZONE_NAMES
WHERE UPPER(TZNAME) = UPPER('America/New_York');
-- Test timezone conversion safely
SELECT
FROM_TZ(CAST(SYSDATE AS TIMESTAMP), 'America/New_York') AS LOCAL_TS,
CURRENT_TIMESTAMP AS SESSION_TS
FROM DUAL;
-- Check NLS and timezone-related session parameters
SELECT PARAMETER, VALUE
FROM NLS_SESSION_PARAMETERS
WHERE PARAMETER LIKE '%TIME%';
-- Confirm effective session timezone at runtime
SELECT SYS_CONTEXT('USERENV', 'SESSION_TIMEZONE') FROM DUAL;
For JDBC connections, add oracle.jdbc.timezoneAsRegion=false to your connection URL to force Oracle JDBC to use UTC offsets instead of region names, avoiding the lookup entirely.
Quick Fix Summary
| Scenario | Fix |
|---|---|
| OS timezone not in Oracle | Use +HH:MM offset instead of region name |
| Old DST file | Apply latest timezone patch + run DBMS_DST
|
| Typo in timezone string | Validate against V$TIMEZONE_NAMES first |
| JDBC app error | Add oracle.jdbc.timezoneAsRegion=false
|
Prevention Tips
1. Standardize timezone configuration across all environments.
Always use a verified timezone name from V$TIMEZONE_NAMES or a UTC numeric offset (+09:00) in all connection strings, application configs, and Oracle parameter files. Include a timezone validation step in your server provisioning checklist.
2. Keep the Oracle timezone file up to date.
Subscribe to My Oracle Support alerts for timezone DST patches. Run the following check quarterly and apply patches before DST rule changes take effect in production:
-- Quarterly timezone file health check
SELECT
'Timezone File Version' AS ITEM,
TO_CHAR(VERSION) AS VALUE
FROM V$TIMEZONE_FILE
UNION ALL
SELECT
'DB Timezone',
DBTIMEZONE
FROM DUAL
UNION ALL
SELECT
'Session Timezone',
SESSIONTIMEZONE
FROM DUAL;
Proactive patching is far less disruptive than emergency fixes during a production outage caused by ORA-01882.
📖 Want a more detailed guide?
Check out the full in-depth version (Korean) on oraerror.com — includes detailed analysis, additional SQL examples, and prevention tips.
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