OK my bad (see below)

had a nice email from Sean which says

I really enjoy your blog and what you find and share.
A minor point but the American Victory at Saratoga was 10/17
 and at Yorktown
was 10/19.
It was not the same day but it was certainly a bad week for the
British to lose two complete armies in a war
(during the same week).

Damn wikipedia!