Changing the time zone on a CentOS server is fairly easy.
First, you'll need to know your time zone and/or country. A list can be found in /usr/share/zoneinfo/
The more generic procedure to change the time zone is to create a symlink to file /etc/localtime
# ln -sf /usr/share/zoneinfo/Africa/Johannesburg /etc/localtime
OR you can copy and replace the current local time setting
# cp /usr/share/zoneinfo/Africa/Johannesburg /etc/localtime
To verify that your time zone is changed use the date command:
# date