In the United States, Patriot Day occurs on September 11 of each year, designated in memory of the 2,977 killed in the September 11, 2001 terrorist attacks. Initially, the day was called the Prayer and Remembrance for the Victims of the Terrorist Attacks on September 11, 2001.

On this day, the President requests that the American flag be flown at half-staff at individual American homes, at the White House, and on all U.S. government buildings and establishments, home and abroad. The President also asks Americans to observe a moment of silence beginning at 8:46 A.M. (Eastern Daylight Time), the time the first plane struck the North Tower of the World Trade Center on September 11, 2001.