DST Time Zone Patches missing in 23ai Release Updates

We work right now with a number of customers going live or being live on Oracle Database 23ai already. And tomorrow will be the release date for the quarterly Release Update, in this case for Oracle Database 23.8.0. But you should be aware of one thing: DST Time Zone Patches missing in 23ai Release Updates.

Photo by Jon Tyson on Unsplash

Time Zone patches and RUs?

In January 2023 I blogged about the inclusion of DST Time Zone patches in Release Updates. But later I learned that this applied only to Oracle Database 19c, and not to 21c. I can’t tell you why that is. I’ve been told that we are going to include them only for Long Term Support releases. And certainly, I accepted this. But I’d have expected these fixes then being part of the Oracle Database 23ai Release Updates – which are delivered as Gold Images.

In addition, there was one partially unwanted side effect of including DST fixes into RUs. The DBCA (Database Configuration Assistant) does not have a switch to choose your desired time zone version when you create a new database or CDB. It can be influenced with an environment variable parameter. But this isn’t ideal and sometimes simply impracticable.

$ export ORA_TZFILE=/u01/app/oracle/product/19/oracore/zoneinfo/timezone_38.dat

What do you need to do with Oracle 23ai?

Currently, at least until Oracle Database 23.8, the DST version needs to be updated separately.

Do you HAVE to do it? No, you don’t. At least not everybody. But in case you work globally, it may be needed depending on where your business activities are settling. Hence, while many of you may be lightly ignore it, others may be forced to fetch DST v44 from MOS Note: 412160.1 – Primary Note DST FAQ : Updated DST Transitions and New Time Zones in Oracle RDBMS and OJVM Time Zone File Patches). The fix for Oracle Database 23ai is available already.

Find the latest DST released version:

• RDBMS DSTv44 Patch 37537949
• OJVM DSTv44 Patch 37537990

You may want to read MOS Note 3071901.1 Applying the DSTv44 update for the Oracle Database in addition.

From the July 2025 RU onward, the DST fixes are supposed to be included then.

You can apply the fix online while the database is up and running. There is no interruption needed. And the fix is generic for the release, matching every RU. As far as I am aware, Oracle Database 23ai has DST v43 delivered out-of-the-box.

Further Links and Information

• Jan 2023: Inclusion of DST Time Zone patches in Release Updates
• MOS Note: 412160.1 – Primary Note DST FAQ : Updated DST Transitions and New Time Zones in Oracle RDBMS and OJVM Time Zone File Patches)
• MOS Note 3071901.1 Applying the DSTv44 update for the Oracle Database
• Choose your desired Time Zone version
• ORA-39405 during impdp

–Mike