On what dates did various countries enter into World War 2?

Arranged by entry into the War

Allies:

Poland: September 1, 1939

Australia: September 3, 1939

France: September 3, 1939

India: September 3, 1939

New Zealand: September 3, 1939

United Kingdom: September 3, 1939

South Africa: September 6, 1939

Canada: September 10, 1939

Denmark: April 9, 1940

Norway: April 9, 1940

Belgium: May 10, 1940

Luxembourg: May 10, 1940

Netherlands: May 10, 1940

Egypt: September 9, 1940

Greece: October 28, 1940

Yugoslavia: April 6, 1941

Soviet Union: June 22, 1941

Mongolia: August 9, 1941

Panama: December 7, 1941

Costa Rica: December 8, 1941

Dominican Republic: December 8, 1941

El Salvador: December 8, 1941

Haiti: December 8, 1941

Honduras: December 8, 1941

Nicaragua: December 8, 1941

United States: December 8, 1941

China: December 9, 1941

Guatemala: December 9, 1941

Cuba: December 9, 1941

Philippine Commonwealth: December 9, 1941

Czechoslovakia: December 16, 1941

Mexico: May 22, 1942

Brazil: August 22, 1942

Ethiopia: December 14, 1942

Iraq: January 17, 1943

Bolivia: April 7, 1943

Colombia: July 26, 1943

Iran: September 9, 1943

Liberia: January 27, 1944

Peru: February 12, 1944

Ecuador: February 2, 1945

Paraguay: February 7, 1945

Uruguay: February 15, 1945

Venezuela: February 15, 1945

Turkey: February 23, 1945

Lebanon: February 27, 1945

Syria: February 27, 1945

Saudi Arabia: March 1, 1945

Argentina: March 27, 1945

Chile: April 11, 1945

Axis

Germany: September 1, 1939

Italy: June 10, 1940 (Note: invaded Ethiopia in 1936)

Japan: September 27, 1940 (Note: Japan had been expanding its empire for years before)

Hungary: November 20, 1940

Romania: November 23, 1940

Bulgaria : March 1, 1941 (Note: Eventually would Declare War on Germany in 1944)

Finland : June 26, 1944 (Note: this is only the date they became an active ally having been a co-belligerent since June 25, 1941)

Thailand: January 25, 1942