After thousands of years of scientific and philosophical assessments regarding Time, Aristotle’s original observation that “Time is the measure of change” still gives to us the simple knowledge that Time and motion are inextricably bound together within our awareness.
In our daily experience, time is not only the divider of the physical motions in the world around us but also of our perceptions and ordered concepts of that motion; giving division, order and coherence to our cognitive faculty of psychological consciousness.
And the physical motions of the World around us further divide our lives with time downward from the four seasons of our year into our twelve months, weeks and days. From there we further mark organizational divisions into the hours, minutes and seconds that we live by and in turn, we accurately track those time divisions of motion all the way back up the ladder beginning with the motions of our Atomic Clock's phenomenal changes.
This intrinsic connection between our psychological experience of time  and physical activity, an area studied even by theoretical physics , is also apparent in the physical "machine" wherein all our thoughts arise: our neurological functions at a sub-conscious level prior to the appearance of our perceptions and self-awareness.
Our brain can be likened to a computer and search engine that fundamentally locates and becomes aware of motion; one of its essential functions is that of "motion detector" and Human awareness without motion [and time] is essentially a meaningless idea.
Motion neurologically presents itself in cognitive increments measured in milliseconds of time , but these minuscule "Time-Slices" of Reality in motion do not possess the inherent unity needed for our mind to form psychological perceptions, which are coherent "collections" of these short "moments" which, when strung together form:
".... the specious present, the short duration of which we are immediately and incessantly sensible." ~ William James
The thoughts of James and others led to the founding of Philosophy’s "Phenomenology"  which examines this speciousness of time within our awareness while searching for the cognitive unity that produces our perceptions, our consistent experiences of "Time" and motion.
As an example of Phenomenology’s perspective, picture a row of dominos on a hardwood playing court floor; thousands of them in a straight line that are set into motion by pushing the first one over. It makes contact with the next and the next as they each in turn begin to fall in blurring speed.
At any given moment several of the dominos are neither standing upright nor laying motionless on the floor but are in motion as a group which neurologically presents itself as a moving entity, a 'manifold' of singular dominos in motion.
This is analogous to the progression and adherence of moments of time as a coherence producing 'Group' of connected moments flowing into our future. This is not memory but occurs below our level of lucid perceptions and is called conscious "Retention".
Like the falling dominoes moving as a group through "Time", groups of elapsing moments of time are held in a “manifold” of conscious 'Retention'. And it is within these flowing spans of retention that our coherent perceptions of motions such as trajectories and the connective melodies of music's motion, of all of life's continuity and flowing structures for that matter, form coherently within the stable grid-work of Time.
Reality begins for us with motion and Time and progresses incrementally through expanding "Manifolds of Time" into our consistent perceptual awareness of living- in motion.
 “Atomic clocks give us phenomenal Time by measuring the precise microwave signal emitted by the atom's electrons as they change energy levels: they are accurate to one second in approximately thirty (30) million years and are our ultimate earthly time-keeper. "
"The State of the Art in Timekeeping"
 "The transition from this "subjective" time ... to the time-concept of pre-scientific thought is connected with the formation of the idea that there is a real external world independent of the subject. In this sense the (objective) event is made to correspond with the subjective experience. In the same sense there is attributed to the "subjective" time of the experience a "time" of the corresponding "objective" event."
"SPACE-TIME", by Albert Einstein
"The problem of psychological time"
"The identification of moments of consciousness as quantum jumps between quantum histories suggests that our common sense picture about the time evolution of universe might be badly misguided by the restrictions posed by the basic features of our conscious experience."
Department of Physics, Theoretical Physics Division,
P.O. Box 9 Fin-00014, University of Helsinki, Finland
 "Mental chronometry is the use of response time in perceptual-motor tasks to infer the content, duration, and temporal sequencing of cognitive operations."
 Phenomenology n : 1: the study of the development of human consciousness and self-awareness as a preface to philosophy or a part of philosophy.
2a: (1): a philosophical movement that describes the formal structure of the objects of awareness and of awareness itself in abstraction from any claims concerning existence.
"phenomenology." Merriam-Webster Online Dictionary. 2010.
Merriam-Webster Online. 10 April 2010