According to the American Heritage Dictionary (part of the Yahoo! network) the unofficial holiday celebrated in February is Presidents’ Day — a day to recognize the contributions of past American presidents, not one president.
According to the American Heritage Dictionary (part of the Yahoo! network) the unofficial holiday celebrated in February is Presidents’ Day — a day to recognize the contributions of past American presidents, not one president.

February 19, 2013 at 12:48 pm
In honor [sic] of Yahoo!’s creative writing, I’d like to coin a new term: apostrophobia.
I could, however, settle for “President’s” if we made it either Lincoln or Washington – perhaps alternating years. That might be a bit confusing, though, so it might be better if we compromised and made it a combination Washington/Lincoln observance.
February 19, 2013 at 6:27 pm
I think that Yahoo! writers shouldn’t even try to use an apostrophe. Ever. They should just supply a dozen or so apostrophes at the end of an article and invite the readers to put them in the correct location.