Is time really a tangible entity or just a human measuring concept for movement?

I am talking about in a context where, if everything was still or motionless then nothing could be measured using a time concept or meter. If everything started moving again then we could apply a time concept or meter...

Nothing is ever "still" or motionless. One common, modern means of measuring time is the decay of radioactive isotopes. The smallest unit of demonstrable time measurement, however, is the day--the time it takes the planet to spin once on its axis. All other units, are, of course, arbitrary. Then there's Planck time, just to really mess your head up. Be assured, that were there no humans, or if humans were to disappear, the planets would still spin on their axes, and there would still be relative observable positions of stars--we just wouldn't be here to see them.

But come to think of it, we can actually measure motionlessness by measuring the time period something has been inactive for...

You've not been paying attention, have you--what do you mean by motionless? Those little electrons go zipping around no matter what your attitude is. Really, you just wanted to muse about this, but you aren't really interested in any serious answers, are you. You've got your opinion, and you don't wnat any confusing contradictions.

My suspicion is that time is something real, even if we don't know what. If it didn't exist, we couldn't use it to measure events.

I suspect it can be worse...
...maybe we are all frozen pictures in a 4D movie and only one thing moves, the "reader"...on/off kind of reader for each frame of reference...

So I guess time is only a human concept of measuring momentary motion, frame by frame perhaps? Space time, they say that's the cryptical head banger...