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

Last updated on APRIL 09, 2021

Applies to:

Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Oracle Database - Personal Edition - Version 8.1.7.4 and later
Oracle Database Cloud Schema Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Information in this document applies to any platform.

Purpose

 

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

Note that "sysdate" or "systimestamp" have 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 an 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 what DST (Daylight Saving Time) is, is found in this video.
A map of the world timezones is found on http://www.worldtimezone.com/index24.php
A list with the unambiguous "Macro-region/Region" timezone name for a most country's /locations : http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
A nice conversion website is http://www.worldtimebuddy.com/

There currently are 36 versions of the Oracle RDBMS Time Zone files.


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 DSTv36 patch (and not included in DSTv35) are:

 

+ Volgograd switches to Moscow time on 2020-12-27 at 02:00.
+ Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.

 

The changes included in DSTv35 patch (and not included in DSTv34) are:

++ Morocco springs forward on 2020-05-31, not 2020-05-24.
++ Canada's Yukon advanced to -07 year-round on 2020-03-08.
++ America/Nuuk renamed from America/Godthab.
++ zic now supports expiration dates for leap second lists.

 

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:

http://www.oracle.com/technetwork/java/javase/tzdata-versions-138805.html

  

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.

Scope

This note
* Shows how to see the current 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

Details

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In this Document
Purpose
Scope
Details
 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
 C.1.a) If you upgrade to 10.2.0.4, 10.2.0.5, 11.1.0.6, 11.1.0.7 , 11.2.0.1, 11.2.0.2 ,11.2.0.3 , 11.2.0.4 , 12.1.0.1 or 12.1.0.2,18.x, 19.x  please see:
 C.1.b) If you apply the 10.2.0.4 , 10.2.0.5 , 11.1.0.7, 11.2.0.2 , 11.2.0.3, 11.2.0.4 or 12.1.0.2,18.x, 19.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
 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 11.2.0.1 ( 11.1.0.7 and lower):
 G.2.b) for version 11gr2 (11.2.0.1 and higher):
 G.2.c) for version 12cR1 (12.1.0.1 or 12.1.0.2):
 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
References

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