On this November 11th, lest we forget. Remembrance Day, known informally as Poppy Day, is a memorial day observed in Commonwealth of Nations member states since the end of the First World War to remember the members of their armed forces who have died in the line of duty. Remembrance Day is observed on 11 November in most countries to recall the end of hostilities of World War I on that date in 1918. Hostilities formally ended "at the 11th hour of the 11th day of the 11th month", in accordance with the armistice signed by representatives of Germany and the Entente between 5:12 and 5:20 that morning. "At the 11th hour" refers to the passing of the 11th hour, or 11:00 am. The First World War officially ended with the signing of the Treaty of Versailles on 28 June 1919.