Keeping the clocks on all server and client machines in your cell synchronized is crucial to several functions, and in particular to the correct operation of AFS's distributed database technology, Ubik. The chapter in the OpenAFS Administration Guide about administering server machines explains how time skew can disturb Ubik's performance and cause service outages in your cell.

You should install and configure your time service independently of AFS. Your Kerberos realm will also require a reliable time source, so your site may already have one available.