What is the relation between law and time? How do international lawyers conceive law in time? This chapter aims to answer the question of how international law is situated in time in a paradigmatic fashion. Looking at social time—the common perception of time in society as opposed to individual or astronomical time—the law is an institution defining time but also relying on a temporal conception. The chapter establishes three basic paradigms of how international law has been situated temporally: the paradigm of atemporality, depicting law as eternal and unchangeable; the paradigm of temporality, defining law as ascertainable but changeable; and the paradigm of fluxus, defining the law as necessarily changing, unsteady and moving. The chapter shows how the understanding of international lawyers shifted from the paradigm of atemporality to the paradigm of temporality. It reviews the treatises of international legal scholars and the notion of peace in peace treaties from the 17th to the 20th century. The chapter then goes on to discuss whether there has been a second paradigm shift from the paradigm of atemporality to the paradigm of fluxus. For this purpose three cases are explored: the evolutive interpretation of the notion of security, the changing customary law on state immunities and the principle of sustainable development. The chapter concludes with the outlook of transcending the paradigmatic approach with a cubistic look at the relationship between law and time.