World War 2 By nlennon94 Period: Jan 1, 1939 to Dec 31, 1945 years Sep 1, 1939 germany invades poland Sep 3, 1939 Britain and France declare war on Germany Dec 7, 1941 Japan Bombs Pearl Harbor (US enters war) Jun 6, 1943 D-Day May 7, 1945 Germany Surrenders Aug 12, 1945 Atomic Bomb causes Japan to surrender