The main question about "Rhythm Based Time" (RBT) has been: why invent a second type of time when the early 20th century, "linear" concept, with modifications, has in the past seemed adequate? The answer emerges directly from essay #105: A Brief "Tomorrow" of Time?, where "now time" (detailed description in postscript #112) is the reading on synchronized clocks "everywhere." Einstein, in fact, is credited with this part of the present reality of physics (although he did not use the term "now time"), and he clearly showed, in theory only, that to test this synchronicity on Earth, minute differences in time (differences created by The Special Theory of Relativity) should appear. But what he did not need to concern himself with, was that any such differences would be negligible in biological processes such as "Rhythm Based Communication", where "time windows" (time intervals for allowable biological errors) are used by both transmitting and receiving organisms. 
     So why do we then define a second form of time, called "Rhythm Based Time," as The Perception of Lateness Relative to On Timeness in a plane, orthogonal (at right angles) to "an arrow of linear time?" The answer lies in a description of time as: a "scalar counter," and not as a fourth "spacial dimension" (a detailed description of dimension is now in postscript #121). Scalar time counting thence has the property of being "projectable," onto both space and moving energy or mass, as "time labels" or "timetags," by the brains and minds of living organisms and by various machines constructed for this purpose by the human species. If "now time" is projected onto energy or mass, moving on an infinitesimally small straight line, then it appears as an infinitesimally small amount of "linear time," previously known as part of an "arrow of time." As the event unfolds the "arrow" may bend and the "time labels" will continue to attach themselves (in a figurative sense only) to the accelerating energy or mass. Many human inventions, in fact, inscribe the "time labels" onto such vectors (for example, a standard, hospital cardiograph). But these labels are not time as a "scalar counter" because all time is always "now time," (see postscripts #105 and #112). They are "time labels," which may include distinct information regarding the past (or invented information regarding the future). "Past time" involves only "time labels," which may consist of factual sensory signifiers. "Future time" involves only "time labels," or invented sensory signifiers. 
     Now for the critical question. Why is it necessary to create the concept of RBT? The answer lies in that energy or mass does not move instantaneously in only one "spacial dimension" (along an "arrow of time"). From quantum mechanics we know that there can be rotation or spin and from both quantum mechanics and biophysics we know that such rotation can be rhythmical. "Time labels" on such rhythmical rotations, orthogonal to "linear time," describe the kinematics of RBT. 
     Furthermore the plane of RBT must be precisely orthogonal to the above mentioned "arrow of time" because otherwise there could be generated cases of "now time" that cause the instantaneous "flow" of "linear time" plus RBT, to go backwards from the future into the past; and that seems, with all the power of physical intuition and using the foundations of thermodynamics, to be impossible. Note that linear "time labels" alone can go backwards and still satisfy all the equations of physics. So also can RBT "time labels" change angular direction (from clockwise to counterclockwise for example). In physical reality the former rarely happens, but in biological reality great selective advantage accrues to the communicating organism if the latter is indeed a practical event. So also, such an event may remove some of the mysteries of quantum mechanics.