Constitution Day is a U.S. holiday observed September 17. It commemorates the Sept. 17, 1787, signing of the U.S. Constitution.
Constitution Day was designated as a national holiday in 1994. The law that created the holiday also dicates that all U.S. schools receiving any federal funding must provide instruction directly related to the history of the U.S. Constitution on this day. When the holiday falls on a weekend, schools are encouraged to observe it on the adjoining school day.