The 76-mm air-defense gun M1914/15 was an anti-aircraft gun used during a war that lasted during which dates?
76 mm air-defense gun M1914/15:  Adopted during World War I, the gun remained in production until 1934. World War I: World War I (WWI or WW1), also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918.
28 July 1914 to 11 November 1918