User:SOTO/Forum Archive/The Reference Desk/@comment-6433721-20130212041323/@comment-4189499-20130215072404
From Tardis Wiki, the free Doctor Who reference
Basically, we can't give an exact answer because that would be wrong. However, we can go by the Doctor's own words and say that according to him it must have happened some time before America. Anything more specific/different is purely speculation.