National Pearl Harbor Remembrance Day, also referred to as Pearl Harbor Remembrance Day or Pearl Harbor Day, is observed annually in the United States on December 7, to remember and honor the 2,403 citizens of the United States who were killed in the Japanese surprise attack on Pearl Harbor in Hawaii on December 7, 1941.

On August 23, 1994, the United States Congress, by Pub.L 103–308, 108 Stat. 1169, designated December 7 of each year as National Pearl Harbor Remembrance Day. On November 29, President Bill Clinton issued a proclamation declaring December 7, 1994, the first National Pearl Harbor Remembrance Day. It became 36 U.S.C. § 129 (Patriotic and National Observances and Ceremonies) of the United States Code.

On Pearl Harbor Day, the American flag should be flown at half-staff until sunset to honor those who died as a result of the attack on U.S. military forces in Hawaii. Pearl Harbor Day is not a federal holiday – government offices, schools, and businesses do not close. Some organizations may hold special events in memory of those killed or injured at Pearl Harbor. - via Wikipedia