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Turkey Continues on Daylight Saving Time From 2016 - Impact on Oracle RDBMS (Doc ID 2185562.1)

Last updated on APRIL 04, 2019

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 9.2 to 12.1]
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Information in this document applies to any platform.


** This change is included in DSTv28. Refer to :

Applying the DSTv28 update for the Oracle Database (Doc ID 2190090.1)

To help you see if your database is affected by the Turkish Government decision to stay on Daylight Saving Time permanently.

Clocks will not be turned back to +2:00 in October ,as declared earlier. By not setting their clocks back, Turkey has abandoned the practice of adjusting the local time to and from DST , effectively changing the country's time zone to a permanent UTC offset of plus 3 hours (UTC+3).

For Questions/official statements about the DST change itself, please contact the Turkish Government . 

IANA has updated Time Zone Database to reflect this change 

The affected timezones in Oracle are "Europe/Istanbul" , "Asia/Istanbul" and "Turkey".


Anyone who may be using the timezones "Europe/Istanbul" , "Asia/Istanbul" and "Turkey".

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?

Used abbreviations:
TZ: TimeZone
TSTZ: TimeStamp with Time Zone
TSLTZ: TimeStamp with Local Time Zone


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In this Document
  1) The DATE dataype and SYSDATE
 2) Storing data in the TimeStamp with (Local) Time Zone datatype.
 3) TimeStamp with Time Zone columns are used, how do I see if the "Europe/Istanbul" , "Asia/Istanbul" or "Turkey" timezone is stored?
 4) Database timezone and Session timezone
 5) Oracle DST patches and this change.
 6) The OJVM dst information
 7) Java in the Database home
 8) TimeZone Related Functions
 9) Time Zone Data in the Data Dictionary (SYS):

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