The messianic religions of late antiquity are obsessed with getting the time right, to know the right time – both at the level of daily, weekly, monthly or annual rituals, and at the level of world history. Where the prophet Cassandra can say for herself, ‘the day has come’, the Gospels will insist that everyone must be anxiously aware that ‘the hour is coming and is now here’. The desire to be certain about one’s place in time produces an extended, competitive and argumentative scholarly literature, which is never simply about the correct calibration of time. Rabbinical writing, first of all, is exemplary of these temporal obsessions.