Under the constitution, United States Courts are prohibited from hearing and ruling on any legal case when there is no standing. Thus, for all US jurisdictions, determining the merits of a law restricting the use of time travel is moot without a demonstrable use of time travel as recognized by the courts. At this point, there is no current law on the books and any current violation of existing law cannot be ruled upon until time travel beyond the rate of one second per second is provable.
Similarly, the rights of Aliens, Vampires, and Sentient computer programs do not exist as of this moments as they have not been demanded by entities that hold standing to demand these rights and you cannot legally demand these rights for someone else. Chewbacca, Dracula, and Ultron must file these suits in a court of law in order to have them (Though Spock does have these rights, as he is half-human, and assuming his mother is a United States citizen).
In short, there are no laws which are legally tested to affect time travel in any positive or negative way as of time of writing and it is illegal to hear cases on such matters until time travel is demonstrably proven. Thus far, this leaves the only laws regulating time travel to the the ones found in physics text books. So remember, when dealing with space-time: 6.71 x 10^8 miles per hour: It's not just a good idea. It's THE Law!