I think the essential problem with time is that since we experience reality as flashes of perception, then we think of time as the point of the present moving, or "flowing" from past to future. Which physics codifies as measures of duration and then correlates with measures of distance, using the speed of light, to postulate spacetime as foundational dimensional extension.
Yet a more efficient explanation is that it is action turning future to past. As in tomorrow becomes yesterday, because the earth turns. Which makes time more like temperature, than space. With time, we measure frequency of events, while with temperature, we measure the cumulative energy of frequencies and amplitudes of events.
So physically there is only the present, with past and future as configurations that longer exist, or haven't been manifested.
Different clocks can run at different rates, because they are separate actions. All things being equal, a faster clock/frequency, is using more energy. Sort of like an animal with faster metabolism ages quicker than one with a slower rate, yet remain in the same present. Which goes to the twin paradox.
That different observer will observe events in different order is no more consequential than seeing the moon as it was a moment ago, simultaneous with seeing stars as they were years ago. It is the energy which is being conserved, i.e. always in the present, not the information it manifests and records.
It is this first law of thermodynamics which essentially creates time and gives it direction. The earth turns one direction, not both. Duration is just the state of the present, as the energy creating events changes form. What is measured is the frequency of change.
One could use ideal gas laws to correlate measures of temperature and volume, but as temperature is only foundational to our emotions, bodily functions and environment, not the sequence of perceptions of our rational thought process, we can presume to be somewhat more objective about how it emerges, so we don't assume volume and temperature are the same.
There is the vacuum, as space and fluctuation as the basis of both temperature and change/time.
Time flows from potential, to actual, to residual. Future, to present, to past.
Consider it somewhat analogous of our view of the sun, moving across the sky, from east to west, but which is caused by the earth turning wast to east.