The American flag is flown half-mast to commemorate important dates such as Peace Officer's Memorial Day and Patriot Day. It is also flown half-mast in the event of a national disaster or the death of specific government officers. A flag at half-mast symbolizes mourning and respect for the dead.
The flag flies at half-mast from sunrise to sunset on Peace Officer's Memorial Day, May 15; Patriot Day, Sept. 11; and National Pearl Harbor Remembrance Day, Dec. 7. In the event of the death of a sitting or former president, the flag flies at half-mast for 30 days. When a sitting vice president, chief justice or speaker of the House of Representatives dies, the flag flies at half-mast for 10 days.
Select leaders including the president, state governors and the mayor of Washington D.C. can also order flags to be flown at half-mast for other occasions.