Enable NTP on the Cluster
 

How the clocks of all the nodes in your cluster can make synchronize with each other?

just configure NTP correctly on all of them and they will agree with each other implicitly. https://www.google.co.uk/search?q=ntp+howto

You can additionally put each node into all other nodes configurations as additioanl data sources, but they'll prefer to sync to a higher strata if possible, so won't make much difference.