Cosmonaut Sergei Avdeyev holds the world record for TIME TRAVEL. He traveled 0.02 seconds into the future.
Yes, folks, it is possible to travel in time, at least, to travel to the future. There's no time-traveling phone booths. What Avdeyev did to travel in time is to orbit the Earth 11,968 times over the course of 748 days in the Mir space station. By the time his stint in space was over, he had experienced 0.2 seconds less than the rest of the world did.
This made him 0.2 seconds younger than he would have been if he had never gone into space. To put it in another way, he traveled 0.02 seconds into the future.
Hypothetically, you travel a whole lot more in time if you traveled faster, closer to the speed of light.
Confused? Perhaps Carl Sagan can explain it better in this interesting video.
(source 1, 2)