Error "ORA-01882 timezone region not found" when creating new domain in Oracle® WebLogic

The problem

During domain configuration I received an error saying ORA-01882 timezone region not found when I clicked on the Get RCU Configuration button.

The cause

This is because your operating system is either using a invalid timezone value, or using the Etc/UTC or Universal timezone. The two latter examples are due to a bug when connecting to the database. 

The solution

1. Exit the domain configuration assistant
2. Set a timezone value accepted by the database: TZ=UTC; export TZ
3. Start the domain configuration assistant again by running config.sh
4. To prevent the same issue from happening again (assuming you hit the bug), you should add the corrected TZ to the software owner's profile, e.g. in $HOME/.bash_profile if you are using the Bourne Again Shell. However, if your Linux server clock is configured with an invalid timezone, you should fix it at Linux level by using a IANA compliant timezone.