You are travelling forward in time currently.
Relativity states clearly that you can choose the rate at which you travel forward in time. You can either slow down or speed up that rate, by living in a valley or at the top of a mountain, respectively. You can't travel back in time though because time is an artificial measure of the motions of things. It is the things that have to be returned to a previous state. There is no mechanism that would spontaneously move all the particles in the universe to their previous positions.