Amy's wedding took place on the day of broadcast of "The Big Bang" -- June 26, 2010. I think Amy's timeline works like this:
1996: Amelia Pond, aged seven, meets the Doctor
2008: Amy Pond, aged nineteen, remeets the Doctor and fights the Atraxi
2010: Amy Pond, aged twenty-one, remeets the Doctor, travels with him, and marries Rory
Therefore, the TARDIS must travel in time to reach Amelia's backyard.