Abstract
It is sometimes argued that there is an analogy between time and modality: What is true of time, mutatis mutandis, should be true of modality, and vice versa. However, I think that the importance of this analogy has not been truly appreciated in the literature. In this paper, I try to offer a plausible account of the relationship between time and modality based on what is known as presentist ersatzism. If the attempt succeeds, it will be shown that ersatzists about time are better able to explain what possible worlds are.