Time Flows at 1 B-second per A-second Paul Merriam What is the rate of temporal flow is a classic question (Skow 2012). I would like to suggest that the rate of time's flow is 1 B-second per A-second, where a B-second is a second as defined by McTaggart's Bseries and an A-second is defined by McTaggart's A-series (McTaggart 1908). This rate is the change in B information per A information. In the most natural 'hybrid' theory of time the two series are not interreducible, so have different dimensions, and this is a genuine rate. I would suggest that it is also possible to compare the B information of a moving frame to the B information of a reference frame, and that that is what relativity does. References McTaggart, J. E.(1908). The Unreality of Time. Mind: A Quarterly Review of Psychology and Philosophy 17 456-473. http://www.ditext.com/mctaggart/time.html Skow, B. (2012). One Second per Second. Philosophy and Phenomenological Research 85(2), 377-389. http://web.mit.edu/bskow/www/research/sec-per-sec.pdf