The hidden date for this stamp can be found along the bottom edge of the stamp.
During the early days of the Second World War, Canadian citizens and the postal authorities believed that Canadian postage stamps current since 1938, should be replaced by new designs. The Department decided to show Canada's contribution to the war effort of the Allied Nations. On Dominion Day, 1st July, 1942, the Department issued stamps portraying King George as head of the Armed Forces in naval, military and air force uniforms.
Portrait of His Majesty King George VI in Royal Air Force uniform, from a portrait by Hugh Cecil of London, England.