1961 The Campaign Medal for the Vietnam War has a Green & White striped ribbon with a scroll banner that has the dates of the war embossed on it: 1961-1975. Most veterans received their Medal before the war ended so many still have one that only has the start date and the end date is void.
The accepted start date is 1 September 1939 with the German invasion of Poland although there had been fighting going on before that date. World War 2 was finally over with the Japanese surrender on 2 September 1945. So officially 6 years and 1 day.