Independence Day - Wikipedia

An Independence Day is an annual celebration[?] commemorating the anniversary[?] of a nation's creation as an independent state, usually by ceasing to be a colony of another state. Many countries have a public holiday on their Independence Day.

Independence Days around the world:

Albania's Independence Day is November 28. It was proclaimed by Ismail Qemali and signaled the end of five centuries of Ottoman rule in Albania.
Argentina - July 9, marking independence from Spain
Central American Independence Day is 15 September, celebrated in Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica, the former states of the United States of Central America, who achieved indepedence from Spain and Mexico on this date.
Colombia - 20 July
Finland - December 6
India's Independence Day is August 15. Pakistan celebrates its Independence Day on August 14. On the midnight of August 14-15, 1947 the British occupation of India ended and two independent nations of India and Pakistan were born.
In the State of Israel, Independence Day (yom ha-a'tzmaut) is celebrated on the Hebrew date of 5 Iyar (unless that falls on Shabbat, in which case it is the 3rd) which occurs usually at the end of spring (May). The Gregorian date for the day in which Israel independence was proclaimed is May 14th. See also Jewish holidays.
Mexico's Independence Day celebration is held on September 16. See Fiestas Patrias for more details.
Panama - November 3, independence from Colombia in 1903.
Poland's Indepedence Day (Swieto Niepodleglosci) is on November 11 in memory of the restoration of Polish independence in 1918. There is also a public holiday on May 3, celebrating the first Polish constitution (which was second in the world after the United States Constitution) proclaimed in 1791 (Swieto konstytucji 3 Maja).
Russia's Independence Day is June 12. See Russia Day.
In the United States of America, Independence Day is a public holiday celebrating the Declaration of Independence held on July 4. It is commonly associated with fireworks displays, barbecues, picnics and other public celebratory events.