Well because time's relative. In actuality, time is a human construct and the Universe is too big to really be constrained by it, so what year it is is really... very relative. But that's the best way I could use to figure out what year it would be on earth, relative to where we are now. But there's probably a million wormholes, stars, planets, galaxies and what not between us that would mess with time, therefore making it very hard to really know.
So uh, best thing I could say is teleport to earth, and find the year it is there at that time, and then just call it that time.