There are two -although abandoned - stories about Time-Travel in Tolkien´s writings.The first one -"The Lost road" - is about two men, father and son, called Alboin and Audoin who travel in time to the fall of Númenór by the angelic intervention of Eonwe.The second one -"the Notion club papers" - is about a group of men who travel into past and future by mind and see the history of middle-earth in the far past and prophesize space travel in the far future.