In ScienceFiction, TimeTravelers are typically persons who by some means are transported into a different time period. While forward movement in time is an acknowledged outcome of Einstein's TheoryOfRelativity?, backward movement has yet to be discovered. It is questionable whether scientists could ever send even a single QuBit of information backward in time.
One exception might be the use of a WormHole. Those who want to test for the existence of TimeTravelers at any point in the distant future may want to participate in a TimeTravelThoughtExperiment.
See also SpecialRelativity, GeneralRelativity, TimeTravel, TimeTravelThoughtExperiment, WormHole