This last wizard lets you set up a time server for your internal network. The protocol used is NTP. You will first have to choose whether you want to rely only on yourself or on an external server in order to get the correct time (Figure 8.21).
If you choose to rely on an external server, the wizard will ask you two time servers to query, in the order of preference. As the help text says, choose a server which is closest to you geographically! You may also have to set your time zone, but normally you will not have to change it: by default, the time zone used during installation is selected (Figure 8.22).