Too Long; Didn't Read
I was just re-reading Leslie Lamport’s classic paper, <a href="http://amturing.acm.org/p558-lamport.pdf" target="_blank">Time, Clocks and the Ordering of Events in a Distributed System</a>. Most of the paper deals with a discussion of how to manage events ordered by logical clocks rather than physical clocks. Of course since the paper was written there has also been much interesting academic and practical work done on how to leverage well-synchronized physical clocks as well (where obviously all the magic is in defining what “well-synchronized” means and how it is accomplished).