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Primary Note DST FAQ : Updated DST Transitions and New Time Zones in Oracle RDBMS and OJVM Time Zone File Patches (Doc ID 412160.1)

Last updated on APRIL 04, 2024

Applies to:

Oracle Database Backup Service - Version N/A and later
Oracle Database - Enterprise Edition - Version and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Database Cloud Schema Service - Version N/A and later
Information in this document applies to any platform.



To give an overview of all existing Oracle RDBMS DST updates and the related notes.

Note that "sysdate" or "systimestamp" has no relation with the Oracle RDBMS DST patches, sysdate/systimestamp is pure depending on the Operating system clock.
So if you have a "wrong database time" after a DST transition updating Oracle RDBMS DST patches will NOT solve your issue, please see <note 1627439.1> How to diagnose wrong time ( SYSDATE and SYSTIMESTAMP) after DST change, server reboot, database restart or installation when connecting to a database on a Unix server.
The Oracle kernel itself is also not impacted by the OS/system clock changes (or for that matter Oracle DST patches). <Note:1013279.6> How Does Daylight Savings Time Affect The Database Kernel?

Please DO note that even if you are located in a country that has changed the DST start or end day in many cases there is no need to "update the Oracle RDBMS DST information".

If your OS has been patched or correctly configured the the "oracle time" (= sysdate) will be correct.
Only if the actual timezone is used in (PL)SQL an "Oracle RDBMS DST" update is needed.

An excellent introduction to what DST (Daylight Saving Time) is, is found in this video.
A map of the world timezones is found on
A list with the unambiguous "Macro-region/Region" timezone name for a most country's /locations:
A nice conversion website is

There are currently 43 versions of the Oracle RDBMS Time Zone files.

Latest DST released version: RDBMS DSTv43 Patch 36260493 and OJVM DSTv43 Patch 36260537

<Note 3002390.1> Applying the DSTv43 update for the Oracle Database

To apply the latest see point "C.1.c) To update a database to a new DST version please check the relevant advisory note:" in this note.

All time zone file updates are cumulative, meaning a newer Oracle RDBMS / OJVM DST patch has all the changes of the previous updates.

All information is derived from the IANA Timezone (Olson) database (mailing list archive is here and release archive is here)
This information is offered "as is".

The changes included in the DSTv43 patch (and not included in DSTv42) are listed below:

This is a combination of [tz-announce] 2024a release & [tz-announce] 2023d release.
2024A Briefly:
     Kazakhstan unifies on UTC+5 beginning 2024-03-01.
     Palestine springs forward a week later after Ramadan.
     zic no longer pretends to support indefinite-past DST.
     localtime no longer mishandles Ciudad Juárez in 2422.

   Changes to future timestamps:
    Kazakhstan unifies on UTC+5.  This affects Asia/Almaty and Asia/Qostanay which together represent the eastern portion of the country that will transition from UTC+6 on 2024-03-01 at 00:00 to join the western portion.
2023D Briefly:
     Ittoqqortoormiit, Greenland changes time zones on 2024-03-31.
     Vostok, Antarctica changed time zones on 2023-12-18.
     Casey, Antarctica changed time zones five times since 2020.
     Code and data fixes for Palestine timestamps starting in 2072.
     A new data file for timestamps starting now.

   Changes to future timestamps:
    Ittoqqortoormiit, Greenland(America/Scoresbysund) joins most of the rest of Greenland's timekeeping practice on 2024-03-31, by changing its time zone from -01/+00 to -02/-01 at the same moment as the spring-forward transition.  Its clocks will therefore not
     spring forward as previously scheduled.  The time zone change reverts to its common practice before 1981.


The changes included in the DSTv42 patch (and not included in DSTv41) are listed below:

Changes included in TZDATA2023C

Full details are here

Release 2023c - 2023-03-28 12:42:14 -0700

Changes to past and future timestamps

Model Lebanon's DST chaos by reverting data to tzdb 2023a.

Release 2023b - 2023-03-23 19:50:38 -0700

Changes to future timestamps

This year Lebanon springs forward April 20/21 not March 25/26.

[This was reverted in 2023c.]


Release 2023a - 2023-03-22 12:39:33 -0700


Egypt now uses DST again, from April through October.

This year Morocco springs forward April 23, not April 30.

Palestine delays the start of DST this year.

Much of Greenland still uses DST from 2024 on.

America/Yellowknife now links to America/Edmonton.

tzselect can now use current time to help infer timezone.

The code now defaults to C99 or later.

Fix use of C23 attributes.

The changes included in the DSTv41 patch (and not included in DSTv40) are listed below:

Changes included in tzdata2022f & tzdata2022g
--The 2022f release of the tz code and data is available.

This release contains the following changes. The most urgent one is the

change for Chihuahua, Mexico which affects timestamps starting Sunday.


Mexico will no longer observe DST except near the US border.

Chihuahua moves to year-round -06 on 2022-10-30.

Fiji no longer observes DST.

Move links to 'backward'.

In vanguard form, GMT is now a Zone and Etc/GMT a link.

zic now supports links to links, and vanguard form uses this.

Simplify four Ontario zones.

Fix a Y2438 bug when reading TZif data.

Enable 64-bit time_t on 32-bit glibc platforms.

Omit large-file support when no longer needed.

In C code, use some C23 features if available.

Remove no longer-needed workaround for Qt bug 53071.

Changes to future timestamps

Mexico will no longer observe DST after 2022, except for areas

near the US border that continues to observe US DST rules.

On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves

from -07 (-06 with DST) to year-round -06, thus not changing

its clocks that day. The new law states that Chihuahua

near the US border no longer observes US DST.

Fiji will not observe DST in 2022/3.

For now, assume DST is suspended indefinitely.

--The 2022g release of the tz code and data is available.

The northern edge of Chihuahua changes to US timekeeping. Much of Greenland stops changing clocks after March 2023.

The changes included in the DSTv40 patch (and not included in DSTv39) are listed below:

Changes included in TZDATA2022E & TZDATA2022D

Jordan and Syria are abandoning the DST regime and are changing to permanent +03, so they will not fall back from +03 to +02 on 2022-10-28.


Palestine now springs forward and fall back at 02:00 on the first Saturday on or after March 24 and October 24, respectively.


Current non-historical changes to the start and end date of DST for some regions / country's that are not included in DSTv34 ( IANA Timezone (Olson) database tzdata2019b update) , if any , can be found here:

To see if your system is affected when a times changes from DST start and/or stop date please use the respective documents. For example:

North Korea switches back from +0830 to +09 on May 2018- Impact on Oracle RDBMS <Note 2428170.1>

Brazil to Start DST on November From 2018 Onwards- Impact on Oracle RDBMS <Note 2331560.1>

Fiji ends DST on 14 January 2018 - Impact on Oracle RDBMS <Note 2331560.1>

For other Timezones than the ones in the notes you can edit the provided script with the timezone name that you want to check.


This note
* Shows how to see the currently installed version of the RDBMS / OJVM patch on your server
* Lists the current available DST advisories
* Answers some common questions.
* Lists the updated time zones between each version of the RDBMS DST updates.

We strongly recommend to have a look at these 2 FAQ's:
<NOTE:340512.1> - Timestamps & time zones - Frequently Asked Questions
<NOTE:227334.1> - Dates & Calendars - Frequently Asked Questions

Used abbreviations:

TZ: TimeZone
TSTZ: TimeStamp with Time Zone
TSLTZ: TimeStamp with Local Time Zone
OJVM: Oracle Java Virtual Machine


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In this Document
 A) How to find the currently installed version of the RDBMS DST patch ?
 A.1) 8.1.7 and lower have no database support for Timezones.
 A.2) for 9i you can use the utltzver.sql script
 A.3) for 10g and 11gR1 query v$timezone_file
 A.4) for 11gR2 and higher query v$timezone_file or DATABASE_PROPERTIES
 A.5) possible confusing outputs in 11gR2 and higher:
 B) How can I see what OJVM DST patch is applied?
 C) Notes covering the current DST available updates
 C.1) Oracle RDBMS and OJVM DST related notes - How to upgrade DST in Oracle Database
 C.1.a) If you upgrade to,,, ,, , , , or,18.x, 19.x, 21.x please see:
 C.1.b) If you apply the , ,, ,, or,18.x, 19.x, 21.x patch set please see:
 C.1.c) To update a database to a new DST version please check the relevant advisory note:
 C.1.d) DST patches list including Latest DST released Version
 C.1.e) How to monitor DST progress and estimate the time it takes
 C.2) Enterprise Manager (Grid Control OMS, Repository and Agents )
 C.3) Oracle Applications
 C.4) Java in the Database home
 C.5) Oracle solaris
 D) Do I need to reapply DST patches each year?
 E) I'm on DSTv <insert current version of your db or client> , do I NEED to apply newer DST patches?
 E.1) For the Oracle RDBMS DST patches:
 E.2) For the OJVM DST patches
 E.3) Can I "downgrade" to a lower DST version?
 F) Can I rely on the Oracle Timezone data?
 G) For what versions are DST patches provided / there is no DST version X for my Oracle RDBMS version?
 G.1) for what Oracle RDBMS versions are DST patches provided?
 G.2) How to apply RDBMS DST patches manually for versions who are not provided:
 G.2.a) for versions lower than ( and lower):
 G.2.b) for version 11gr2 ( and higher):
 G.2.c) for version 12cR1 ( or
 H) Overview of what DST version is by default used/included in what Oracle RDBMS version and all DST patch numbers
 I) What timezones are known / I'm missing timezones in the Oracle Database / should I use acronym timezone names like CET, PST, NZ etc ?
 J) List of updated Timezones in RDBMS DST updates
 K) List of synonyms known in the Olson database
 L) Active Data Guard Considerations:
 M. Steps/Scripts to upgrade DST:
 N. How to change dbtimezone:

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