Rethinking multi-grain timestamps

At this point, you need some old guy to point out the definitive discussion of this: Time, Clocks, and the Ordering of Events in a Distributed System
https://lamport.azurewebsites.net/pubs/time-clocks.pdf (1978) by Leslie Lamport. As you would expect from him, it's beautifully written. Everybody concerned with this issue should read it.

--David