A (would-be) sophisticated answer to the question of the title might be, ‘The question is senseless. We should not conceive of time at all. We should just get on with our ordinary lives, asking and answering the usual questions, such as “What Time is it?”, “How long will it take?”, and so on, which we understand perfectly well. St. Augustine understood such questions, phrased in Latin, as well as we do. He should have been content with that, instead of bothering his head with the misbegotten metaphysical question, “What is time?”’.