November 11th is an important day in both America and Canada. In each case, the day is set aside to remember fallen armed forces members who died in World War I. The day was proclaimed in 1919 by both King George V and President Woodrow Wilson, exactly one year after the war officially ended, "at the 11th hour of the eleventh day of the eleventh month" on 1918, when the Germans signed Armistice.
In Canada, the symbol for Remembrance Day is the red poppy -- the use of which stems from a famous poem called In Flanders Field, written by a Canadian soldier named John McCrae during the Second Battle of Ypres in 1915. Poppies bloomed across some of the worst battlefields of the Flanders in WWI, their brilliant red color an appropriate symbol for the blood spilt in the war.
In the US, the day is referred to as Veteran's Day, and was expanded to include the fallen heroes of all armed conflicts in which American armed forces have taken part.