Hi,
I have recently upgraded from 11.2.0 to 12.1.0. Oracle suggests to run a number of scripts after upgrade (like postupgrade_fixups.sql). So, when I ran it, it listed a couple of recommendations:
Beginning Post-Upgrade Fixups...
**********************************************************************
Check Tag: OLD_TIME_ZONES_EXIST
Check Summary: Check for use of older timezone data file
Fix Summary: Update the timezone using the DBMS_DST package after upgrade is complete.
**********************************************************************
Fixup Returned Information:
INFORMATION: --> Older Timezone in use
Database is using a time zone file older than version 18.
After the upgrade, it is recommended that DBMS_DST package
be used to upgrade the 12.1.0.2.0 database time zone version
to the latest version which comes with the new release.
Although it says that timezone datafile is of older than 18 version, this says that it is not:
SQL> SELECT version FROM v$timezone_file;
VERSION
----------
18
Whom to believe?