Let us imagine frames of time like spaces between the bicycle wheel's spokes. Close to the center id needs just small velocity difference, and in the very middle there's no time at all. Obviously a being, either living by the center or by the periphery, he would be able to see the difference of line velocity only if he would perceive in a way a world of different distance from the center. There are time deviations, as beings or particles don't remain in the same zone all the time, but through twists of the centrifugal and centripetal forces' constitution they travel in relation to the radius. Of course single particles' travelling is more common, as because of their small mass they're more independent from the law of inertia than galactics are.
Time is existence.
It's an attribute, which is that subsequent worlds come one after another. One world, existing in one moment, turns into another one.