 For B-theorists, the only objective temporal facts concern relations of precedence and simultaneity between events. (I ignore here the complications introduced by the Special Theory of Relativity, since B-theory—and perhaps A-theory also—can be reformulated in terms which are compatible with the Special Theory.) B-theorists do not deny that our tensed beliefs, such as the belief that a cold front is now passing, or that Sally’s wedding was two years ago, may be true, but they assert that what makes such beliefs true are not facts about the pastness, presentness or futurity of events, but tenseless facts concerning precedence and simultaneity (see Mellor 1998, Oaklander and Smith 1994). On one version of the B-theory, for example, my belief that there is a cold front now passing is true because the passing of the front is simultaneous with my forming the belief. Now one very serious challenge to the tenseless theorist is to explain why, if time does not pass in reality, it appears to do so. What, in B-theoretic terms, is the basis for our experience as-of the passage of time?