Maya codices were important repositories of cultural knowledge and traditions passed down through the centuries. Rather than being focused on human actors, however, the Late Postclassic period Maya screenfolds contain almanacs that predict the movements of celestial bodies during earlier time periods. The purpose of these seemingly “out-of-date” tools was to predict the future based on notions of cyclical time. Recent research suggests that centuries-old astronomical almanacs do more than model the past or formulate rituals. Instead, they are formulated to integrate celestial events with other cycles of time and to contextualize them with events from the mythic past, such as the destruction of a former world by flood. The memory of this calamitous primordial event, framed in terms of astronomical and seasonal cycles, is preserved in pre-Hispanic and historic documents as a means of conveying the ill-fortune associated with like-in-kind events that are certain to repeat, and of scheduling the performance of appropriate ritual actions to mitigate their destructive potential.