3 May Constitution Day (also 3rd May National Holiday; Polish: Święto Konstytucji 3 Maja) is a Polish national and public holiday that takes place on 3 May. The holiday celebrates the declaration of the Constitution of 3 May 1791. Festivities date back to the Duchy of Warsaw early in the 19th century, but it became an official holiday only in 1919 in the Second Polish Republic. Delisted during the times of the People’s Republic of Poland, it was reestablished after the fall of communism in modern Poland.