I just have to chip in, here. In the Star Wars EU, humans have no "known" home world, and just showed up on the city- world Coruscant 100,000 years before the events of "A New Hope". I'm a bit of a geek, so I've read just about every book written. The only reference to calendar years are that the cycle of years is based off Coruscant's orbit, and Coruscant is a bit further out from its sun than Earth. One novel, 'Millenium Falcon' mentions that the Falcon is a rebuilt Yt-1300 that was built in'18, and was about 60 years old when Han acquired her, so that puts 'A New Hope' in approx. '78. ( note, the novel doesn't specify what, if any digits come before the last two digits of the year, but it doesn't much matter, since another novel specifies that the calendar under which the Falcon was built was based off the founding of the Republic, which was 4000 years before 'ANH', and was changed to count years from the founding of the Empire after the Empire overthrew the Republic).
Whew, sorry for being long- winded, but I'm a nerd.
On a side note, I don't think ( and this just my fan theory, here) , that it is a galaxy far, far, away. If you align the Star Wars galaxy and the Milky Way, you'll find that Earth could easily sit within a section of uncharted space called the Unknown Regions. Food for thought, or wishful thinking from a fan boy?
Klik