Time is nothing more than measurement relative to observation.
In everyday terms, the measurement of time compares the duration of the clocked event relative to an agreed-upon standard, such as the motion of the earth, etc.
You are incorrect. Time is a necessary component of the 2nd Law of Thermodynamics. Our attempts to measure time are arbitrary, as a "second" is no more a universal constant than is a meter. But the flow of time is a consequence of the 2nd Law of Thermodynamics, as entropy would have no meaning if time was a human "invention" or simple product of human observation.
Second, the motion of any body within a uniform gravitational field can be best described as that path that takes the longest proper time, or, from another perspective, an object in a gravitational field always moves from one place to another so that a clock carried on it gives a longer time than it would on any other possible trajectory. So regardless of any units you use to measure it, time does have a real existance outside of observation, because it directly effects the behavior of systems without any observation necessary (the planets falling towards an unknown sun behave differently than an object in the Earth's gravitational field, regardless of whether anyone "measures" anything.
Your declaration might have been true if time was a constant, but, like all physical quantities, it is variable. Electricity is not simply a "measurement," even though the units we use to measure electricity are arbitrary and our measurements usually are only of a difference in electrical potential (just like time is measured in differences). Read up on space-time theory and relativity theory and you will see that you are quite mistaken. Time is a quality all its own...
Have you read Julian Barbour's The End of Time?
I read it twice and still don't understand it.
One of my interests is the question of time, its nature.
I 'convinced' myself via a somewhat difficult-to-follow internal debate that "the passage of time is an illusion."
Rudy Rucker once asked Kurt Godel 'what causes the illusion of the flow of time?' Godel answered obliquely, but did not reject the question as nonsensical.
The more I 'study' time, the more confused I become. There is a deep mystery here. I wonder if humans can ever discover the true nature of time.
--Boris
Durn! Guess I'll have to trade in my watch for a tape measure now.
Boss: "Hey, Mort! You're two feet late for work."
Mort: "Sorry, Boss. My son left my tape measure at the drag strip."
I too have often wondered if time is truly a "dimension" or merely the result of "activity" such as an electron revolving around its nucleus and expanding that concept outward from there. Once there is activity or motion of some sort time then becomes only how we observe it and measure it. I’ve read excellent discussions about this on Space.com.