Philosophical development of Leibniz's view that time is merely earlier–later order is necessary because neither Leibniz nor modern followers sufficiently answered the Newtonian charge that order does not give quantity. Logically, order is transitive, quantity, as in distance, is not. Quantity, as well as order, is naturally assumed in Newton's absolute time, so that to declare the mere relative order sufficient is to have to show how quantity can arise for it. The modern theory of the continuum, perfectly applicable to Newton's absolute, does not show this but assumes quantity. The development given here shows how interval, instant and simultaneity can be logically developed from Leibniz's insight.