We show how synchronized clocks can be realized in a distributed system as a byproduct of a common communication paradigm where processors periodically perform broadcasts. Our approach decouples the precision concern of clock synchronization-limiting how much correct clocks can differ from each other-from the accuracy concern-limiting the rate at which any correct clock may drift from real time. Given a system that guarantees only precision, we develop a protocol whereby high accuracy can be achieved on demand. In this manner, the "lazy" protocol we obtain incurs the cost of high accuracy only when needed while keeping the basic synchronization procedure extremely simple and cheap. © 1993 Springer-Verlag.64193203