In a moment of boredom I was thinking about mass and gravity and pondered the possibility that time is a function of mass. i.e. time cannot exist without mass. Gravity is a function of mass, so why not time. I guess I should go and research this and I am sure someone has already thought about this question years before me (as they usually do.)
If only two objects exist in the universe, both very distant from each other. They will exert, however minute, a gravitational force on each other.
Time, from an outside observer’s point of view, slows down for any object as it approaches a massive object, until time effectively comes to rest for the observed object. It is reasonable to assume that time will “speed up” as the objects move away from each other. For the massive object, from an outside observer’s point of view, this would be an almost imperceptible increase, but for a smaller object moving away from a massive object, the increase in the rate of time would be dramatic. It must be assumed that “time” is faster the further away the objects are from each other. At an infinite distance time MUST “speed up” to infinity. In the absence of mass, time could not exist just as gravity cannot.