Time, like space is not absolute. Each FoR experiences the passage of time at one second/second in relation to his own mechanical and biological frame. But each frame will see time passing at different rates in another frame, dependent on gravititational potential and/or speed relative to his/her own frame. The same applies to space. As Minkowsky after Einstein formulated SR said..... "The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality". Hermann Minkowski: That's what relativity is all about.