December 8th 1941
The United Kingdom officially declared war on Germany on August 4, 1914, thereby entering World War I.
The war in Europe officially ended with a German surrender on May 8, 1945.
You have to be a little more specific on which war you are talking about. World War I officially began on July 28, 1914. World War II officially began on September 1, 1939 (although some countries were already fighting, notably that Japan was already fighting China).
World War 2 officially started on 1 September 1939 when German troops invaded Poland. Austria and Czechoslovakia had been annexed by Germany before that date.
There are two dates said to be the end dates of world war two. First date is August 14, 1945 and other is September 2, 1945 both dates are the dates when Japan surrendered.
april,28,1914
April 6th 1917
in 1915
The United Kingdom officially declared war on Germany on August 4, 1914, thereby entering World War I.
May 8th 1945.
December 7, 1941
Germany invaded Poland on 1 September 1939, which is the official start date of World War 2, not World War 1
We entered the war in 1941 after the attack on Pearl Harbor. And then after we declared war on Japan, Germany and Italy declared war on us, officially starting WWII.
7th December, 1941. A date which will live in infamy --
Officially, when Japan attacked the US Pacific Fleet at Hawaii, December 7 1941.
Officially World War 2 ended 9/2/45 when the Allies and Japan signed The Instrument of Surrender on the USS Missouri.
The war in Europe officially ended with a German surrender on May 8, 1945.