Happy 12/12/12! December 12, 1912, that is.
From the New York Evening World, December 12, 1912
Interesting that they had to interview a Chicago civil engineer for this, as the first point seems rather obvious, and the second point, rather random.
Below: Twelve women from Morrisania, the Bronx, picture date unknown (NYPL)
link to the New York Times' take
on this unusual date back in 1912.