There are two conspicuous and inescapable features of this world in which time is real. One experiences a world in flux, a transient world in which things constantly come into existence, change and cease to be. One also experiences a stable world, one in which how things are at any given moment is permanent, unchangeable. Thus, there is transience and permanence. Yet these two features of the world seem incompatible. The primary purpose of this paper is to sketch a metaphysics of time that embraces both features. Crucial to this undertaking is the notion of becoming, that is, coming into existence. I distinguish three distinct phenomena of becoming: temporal, absolute and atemporal. The last is the least familiar of these; it is the phenomenon of coming into existence outside of time. Although the idea that there are things that do not exist in time is not unfamiliar, it is largely taken for granted that if anything comes into existence, it must do so in time. (Indeed, I suspect many think that the idea of a thing coming to be outside of time is simply incoherent.) In this paper, I articulate and defend the notion of atemporal becoming. It is by means of this notion that one can develop a fully satisfactory metaphysics of time, one that honors both transience and permanence and finds for each its proper domain within the world.