Yes.... time as a concept is all the above. BUT, the way we measure and keep track of it is a strict progression of cause and effect. The timing provided by passing current through a crystal of quartz is neither theoretical or subjective. Clocks are machines. Some machines are better than others, ie more accurate. "The time keeping machine in my car is inaccurate while others are not, therefore my machine is defective, poorly made or doesn't make use of existing technology, ie. Auto calibration."