Timekeeping has an interesting history. It has graduated through the centuries according to the needs and desires of Man. It is because of his needs that the relevance manifests. Obviously then, being at a prescribed place at a prescribed time can define itself. Travelling within time, forward or back is an issue that Einstein puzzled over more prolifically than anyone. His own relevance was expressed as E=MC2. Clocks only measure with imperfection, but the increments in which the finest do this, thusfar anyway, exceed the needs of Man's requirements.
Clocks are far more than numbers and springs. Their evolution has brought them to the sharpest edge of technology.
You wouldn't fare any better flying to the moon with a Timex than building a towering skyscraper with a yardstick.
Thanks for an interesting post.
Regards from Max Stout