Exactly. So by saying he could do it in one afternoon, he could travel there and it may take him 42 minutes or a few hours or whatever, but to the rest of us, no time will have passed at all. So theoreticly he could go there, spend some time and come back and the only time that will have passed for us in comparison to him will be whatever time he chooses to spend on Mars. So technically, he could do it in an afternoon