Summer time was first introduced during World War I by the German Empire from 1916 to 1918. After the end of the war and the proclamation of the Weimar Republic in November 1918, summer time ceased to be observed. Summer time was reintroduced in 1940, during World War II, to try to save energy for the war economy. After the defeat of Germany, summer time was retained by the occupation powers. In 1945, Berlin and the Soviet Occupation Zone even observed Central European Midsummer Time ("Mitteleuropäische Hochsommerzeit", "MEHSZ"; GMT+03:00): in 1947, all of Germany switched to midsummer time from 11 May to 29 June. After the Federal Republic (West Germany) and the German Democratic Republic (East Germany) were established in 1949, summer time again ceased to be observed in 1950.