An argument by David Lewis (1980) shows that the following three claims are inconsistent. (1) The compositional semantic value of English sentences are classical propositions (sets of worlds). (2) The compositional semantic value of a sentence relative to a context (what Kaplan calls 'content') is its assertoric content. (3) English contains temporal operators. While Lewis rejects (2), David Kaplan (1989) is naturally read as holding that we sometimes assert temporal propositions (sets of time-world pairs), i.e. as rejecting (1). Is this a plausible strategy? I argue that an influential argument by Marc Richard against temporal propositions as the objects of assertion and belief fails. If there's time, I'll also present what I take to be a better argument against equating Kaplan's 'content' with assertoric content.