How to set the timezone in Ubuntu and CentOS and some other useful time commands

To set the timezone in CentOS or Ubuntu, see examples below:

timedatectl set-timezone Europe/London
timedatectl set-timezone Africa/Johannesburg

For a list of zones, use these commands:

timedatectl list-timezones
timedatectl list-timezones | grep -i europe

Other useful date time commands

This one shows information compared to time sync:

timedatectl

Check if ntp service is running:

service ntp status

Install a more sophisticated time server service (see Notes below):

apt install ntp

Notes:

When you run the above command, you may get this:

Package systemd-timesyncd which provides time-daemon is to be removed