March 8: International Women's Day, first officially declared by Lenin
March 18: Paris Commune Day
April 30: Vietnam Reunification Day marking the Liberation of Saigon
May 1: International Workers' Day (Labor Day)
May 9: Victory Day over Fascism in Europe
July 26: Cuba's National Day marking the start of the Cuban Revolution
September 3: Victory in the People's War of Resistance against Japanese Aggression
October 1: Establishment of the People's Republic of China
November 7: October Revolution Day marking the birth of the first workers' state
(yes the October Revolution was in November, thanks to calendar differences)