Sorry if my question is not really clear, but indeed it is not clear in my mind neither. But maybe some of you can help. Time is not absolute and can be affected by the gravitational potential. Now the question is: do concepts like the age of the Universe, time between different cosmic epochs etc, depend on the position of the observer with respect to a gravitational field? If yes, how much things would change if we were observers, e.g., close to a black hole or in absence of gravity?