Presidents'Day is usually written thus, but the White House website has it as President's Day.
From the economist.com
Presidents'Day is a two-day holiday in Botswana in July.
From the en.wikipedia.org
Presidents'Day is not exactly an anniversary.
From the en.wikipedia.org
Presidents'Day sales are held shortly thereafter.
From the en.wikipedia.org
Presidents'Day weekend typically kicks off the search for a summer home, though agents say they've even had midweek showings recently as some renters jump the gun.