To change the default time zone on a CentOS/Linux server, you can follow these steps:

1. Check the current time and time zone
   Open a terminal or command line window and enter the following command:

   1

   date

   This command will display the current time on the server. If the time zone is incorrect, the displayed time may differ from your local time.

2. Locate the time zone file in /usr/share/zoneinfo
   Execute the following command:

   1	ls /usr/share/zoneinfo/

   This command lists all available time zone files. Choose the appropriate time zone based on your location.

   For instance, if you are in China, you can enter:

   1	ls /usr/share/zoneinfo/Asia/Shanghai

   This command will return a file that indicates the time zone setting for Shanghai.

3. Create a symbolic link for /etc/localtime
   Run the following command:

   1	ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

   If the location of your chosen time zone file is different, replace the path in this command with the corresponding time zone file path.

4. Verify that the changes have taken effect
   Run the following command again:

   1

   date

   If the time displayed matches your local time zone, you have successfully changed the default time zone on the server.

Additionally, if you are running CentOS on a virtual machine, make sure that the time zone settings on both the host and the virtual machine match.