In Russia, Ukraine, Belorussia and other countries of former Soviet Union, the day of Victory over Nazi Germany was celebrated on May 9, because when the German Instrument of Surrender actually entered into force (May 8, 1945 at 23:01 CET), it was already May 9 by Moscow Time. Some post-Soviet countries, most notably The Russian Federation, have continued the tradition. Serbia, not the part of the Warsaw Pact, but in Yugoslavia it was allied with the Soviets, and its people heavily suffered under the occupation, fighting the german forces until the liberation, celebrates this day too. It's a national holiday. People gather on the main square in many cities to mark the anniversary with the war veterans, including Serbian army.