What Days do You Fly the American Flag Half Mast?

It is customary to fly the American Flag at half staff on the following days: Peace Officers Memorial Day, May 15th (sunrise to sunset), Memorial Day, last Monday in May (sunrise to noon), Patriot Day, September 11th (sunrise to sunset), Pearl Harbor Remembrance Day, December 7th (sunrise to sunset). Other rules apply to flying half staff for the death of an American President or Statesman.