For making the other one quite irrelevant! But here it goes, anyway.
The concept of a "future" time on this planet is preposterous, due mostly to the fact of the arbitrary location of the Prime Meridian in the first place. When the Prime Meridian was chosen to be established as 0 degrees longitude, is was chosen based on a decision made by a council of representatives from many countries, not by any major geographical locations. The place that was chosen, the middle of Nowhere, England Greenwich, was chosen so as not to give any more importance to any of the world's major cities at the time, like Paris, London, or Washington, D.C. Couple that with the fact that the division of time is a largely fictitious, but accept, concept made for the sole purpose of making our lives easier, basing who is in the "future" and who is in the "past" is a highly preposterous claim to make. We all currently live in the present, and our current position on the globe does not adversely affect our present status in the space-time continuum.
In short, saying you're in the future because you're six hours ahead of me is about as preposterous as claiming the 81.14 Japanese yen is worth more than 1 USD because it's a larger number.