The two dates are July 7th 1937, when the Marco Polo bridge incident led to a longer war between Japan and China, and September 1st 1939, when Germany invaded Poland, which led Britain and France to declare war on Hitlers Nazis state in retaliation.The war in Europe ended with Germany surrender, on may 7th 1945. The war in the pacific ended with japans surrender, on September 2nd 1945.The war ended in the summer 1945, and it is estimated that around 50 million people lost their lives during the world war two.World war two started in 1939-1945.