Armistice Day, later known as Remembrance Day in the Commonwealth and Veterans Day in the United States, is commemorated every year on 11 November to mark the armistice signed between the Allies of World War I and Germany at Compiègne, France, at 5:45 am for the cessation of hostilities on the Western Front of World War I, which took effect at 11:00 am—the "eleventh hour of the eleventh day of the eleventh month" of 1918 although, according to Thomas R. Gowenlock, an intelligence officer with the U.S. First Division, shelling from both sides continued for the rest of the day, ending only at nightfall. The armistice initially expired after a period of 36 days and had to be extended several times. A formal peace agreement was reached only when the Treaty of Versailles was signed the following year.

Remembrance Day is a memorial day observed in Commonwealth member states since the end of the First World War to honour armed forces members who have died in the line of duty. The day is also marked by war remembrances in several other non-Commonwealth countries. In most countries, Remembrance Day is observed on 11 November to recall the end of First World War hostilities. Hostilities ended "at the 11th hour of the 11th day of the 11th month" of 1918, in accordance with the armistice signed by representatives of Germany and the Entente between 5:12 and 5:20 that morning. The First World War formally ended with the signing of the Treaty of Versailles on 28 June 1919.