Hector
Physically (as far as we can know, and this is science not religion), what is happening is that there is alteration in a physically existent state. Only one such state, in any given sequence, can exist at a time, because the predecessor must cease for the successor to exist. Look out the window, a bird flies past, the bush changes colour and loses its leaves, etc. Now, each of the physically existent states which comprise those sequences can only exist one at a time, in a sequence order. The bird is not in different spatial positions at the same time, neither does the bush have/not have leaves at the same time. Neither does any given existent state continue to exist once it is superseded (this flawed thinking reflects the failure to understand that we receive a representation of physical existence, eg light). It is existential sequence, one physically existent state at a time.
One aspect of this is the rate at which that alteration occurs, irrespective of what is altering, and this is what timing calibrates. As with any measuring system, fundamentally this involves comparison to identify difference. So, in the case of timing, the reference is a conceptual constant rate of change. Any given timing device 'tells' the time, ie within the realms of practicality, it is sychronised with this conceptual reference. Again, a practical example. If you use a quartz timing mechanism, what is actually happening. Answer, you are comparing a rate of alteration as manifest in crytal oscillations, with whatever rate of alteration is being timed. In other words, if one literally used the reference, then the result would be expressed in terms of the event started at oscillation x and n oscillations had occurred when it finished. But the oscillations are automatically converted for you into another expression, which is minutes, days, etc, ie the common constant reference. Indeed, if you consider why those labels you realise this is an example of fosilised language, because the first clock was earth movement.
Specifically, I do not state it is all about movement, it is about the rate of alteration, movement just being one example of physical alteration.
Paul