The aim of this paper, in keeping with the theme of this jubilee issue, is to examine the private international law concept of public policy in its temporal dimension. The two main parts of the paper will discuss, in Part 2, the meaning and role of public policy, and, in Part 3, the impact of the ‘time element’ on public policy. This latter subject includes a discussion of both the point in time as of which public policy is applied, and of the way in which the values embodied in public policy change over the years. Part 4 will briefly note the way in which the concept itself, as distinct from the values that give it content, is evolving. For the most part my discussion is from the perspective of Anglo-Canadian private international law, and its counterparts in other British Commonwealth countries, because that is the system (they can be treated broadly as one system) with which I am most familiar. I will refer as well to sources in the United States and elsewhere to illustrate certain points, but neither space nor time have permitted a truly comparative study.