After modifying the time zone setting on the storage cells, you can change the time zone setting on the database servers.

1. Log in to the database server as the root user.
2. Take note of the Oracle Linux version used on the database server.

   For example:

   # cat /etc/system-release
   Oracle Linux Server release 8.8
   

3. Change the operating system time zone configuration.

   Choose the appropriate method based on the Oracle Linux version used on the database server.

   • If the database server uses Oracle Linux 6 or earlier, then copy /etc/localtime and /etc/sysconfig/clock from any of the storage cells to the database server.

     # scp root@cell_name:/etc/localtime /etc/localtime
     # scp root@cell_name:/etc/sysconfig/clock /etc/sysconfig/clock
     

   • If the database server uses Oracle Linux 7 or later, then use the timedatectl command to change the operating system time zone configuration.

     • To view the current time zone configuration, run /usr/bin/timedatectl with no additional options. For example:

       # /usr/bin/timedatectl
                      Local time: Tue 2024-04-02 15:24:16 NZDT
                  Universal time: Tue 2024-04-02 02:24:16 UTC
                        RTC time: Tue 2024-04-02 02:24:17
                       Time zone: Antarctica/McMurdo (NZDT, +1300)
       System clock synchronized: yes
                     NTP service: active
                 RTC in local TZ: no

     • To change the time zone setting, run timedatectl with the set-timezone option. For example:

       # /usr/bin/timedatectl set-timezone America/New_York

     • To view a list of available time zones, run timedatectl with the list-timezones option. For example:

       # /usr/bin/timedatectl list-timezones
       ...
       America/Monterrey
       America/Montevideo
       America/Montserrat
       America/Nassau
       America/New_York
       America/Nipigon
       America/Nome
       America/Noronha
       America/North_Dakota/Beulah
       America/North_Dakota/Center
       America/North_Dakota/New_Salem
       America/Ojinaga
       America/Panama
       America/Pangnirtung
       America/Paramaribo
       America/Phoenix
       ...

4. Change the time zone setting in /opt/oracle.cellos/cell.conf.

   Edit the <Timezone> entry.

   For example:

   ...
   <Timezone>America/New_York</Timezone>
   ...

5. Change the Oracle Clusterware time zone configuration.

   Edit the TZ entry in $GRID_HOME/crs/install/s_crsconfig_<nodename>_env.txt.

   For example:

   TZ=America/New_York

6. Change the time zone environment variable (TZ) setting in the oracle OS user profile. Also change the grid OS user profile, if applicable.

   The following example shows the time zone environment variable (TZ) setting in the bash profile (.bash_profile) associated with the oracle OS user.

   # cat /home/oracle/.bash_profile | grep TZ
   export TZ=America/New_York

7. Change the Oracle Clusterware settings to prevent the CRS stack from starting automatically after restarting the database server.

   # Grid_home/bin/crsctl disable crs

8. Reboot the database server.

   # shutdown -r now

9. Verify that the time zone has been changed on the database server.

   Use the date command verify the time zone change.

   For example:

   # date
   Mon Apr 1 22:26:00 EDT 2024

   If the database server uses Oracle Linux 7 or later, you can also use the timedatectl command.

   For example:

   # /usr/bin/timedatectl
                  Local time: Mon 2024-04-01 22:26:30 EDT
              Universal time: Tue 2024-04-02 02:26:30 UTC
                    RTC time: Tue 2024-04-02 02:26:31
                   Time zone: America/New_York (EDT, -0400)
   System clock synchronized: yes
                 NTP service: active
             RTC in local TZ: no

10. After verifying the new time zone setting on the database server, enable and restart Oracle Clusterware.

    # Grid_home/bin/crsctl enable crs
    # Grid_home/bin/crsctl start crs

11. Verify that the database time stamp matches the operating system time.
    On each database, compare output from the operating system date command with output from the following SQL command:

    SQL> SELECT systimestamp FROM dual;

12. Repeat the previous steps on all of the database servers in the cluster.