Rather than what is commonly assumed to be time, have you ever considered the very entity of time itself?

"The distinction between the past, present and future is only a stubbornly persistent illusion."
--Albert Einstein

From a very fundamental level we see time as energy moving matter through space in some form.
But that on its own does not explain time, you have days that go by faster or slower than some, what feels like time travel as we lose conciousness or sleep, the effect of time dilation and quantum mechanics.

What this all has in common is the observer itself which leads me to think there is some kind of observer bias which gives the illusion of time.
An observer itself takes in senses at certain rates like the FPS of a video camera in our eyes or the vibrations in your ear, which means what we observe is energy move matter through space at a rate of our senses.
Because our senses run on energy it makes sense being able to observe reality that also uses energy to move matter in some form because they are the same thing fundamentally.

Something like sleep can cut off our observation of time which gives the illusion of time going by almost instantly, so this observation gives some insight to how days go by faster or slower.
If a day was filled with activities that are not engaging mentally or sensory while exposed to a slow rate of sensory, say slow paced music the day would appear to go quicker to that observer.
Needless to say the reverse has the opposite effect.

Then considering time dilation, observation rate is increased when traveling through space this has the effect of time slowing down due to a similar effect mentioned in the previous paragraph, where the input to your senses increase with passing objects or wind passing you and so on.
To an external observer it shows the observer traveling through space to be moving faster and in turn a shorter period of time.

The use of time devices is also energy moving matter through space but in a very consistent pattern, this allows us to observe a constant rate of time without having be there to observe it.
So even though we may measure time as things go by to different densities of space, it is still the same observation of energy moving matter through space in some form.

As such the illusion of time is a observational result of energy acting on matter, it is that same process we use to observe our reality that we can observe it.
Since the illusion is within ourselves as observers, it is rational to think that our physical reality has no time of which everything progresses but a constant state of here and now that changes as energy is acted upon matter.
Time is just a measure of a observation of matter, not so much a measure of progression.
This also answers why we haven't met any time travellers in our reality as such concept would not exist logically in this regard.

Thoughts?