National Flag day commemorates the death of Manuel Belgrano, who created the current flag.
The holiday is celebrated on June 20. Prior to 2011, the day was celebrated on the third Monday in June.
The national flag of Argentina dates from 1812. It is a triband, with three equally wide horizontal bands of light blue, white and light blue. In 1818, a ' Sun of May' was added to the center.
The flag with the sun is the Official Ceremonial Flag. The flag without the sun is considered to be the Ornamental Flag. While both versions can be said to be the national flag, the ornamental version must always be hoisted below the Official Ceremony Flag.
During the Argentine War of Independence General Belgrano was leading a battle near Rosario. He noticed that both the Crown's forces and the independence forces were using the same colors (Spain's yellow and red).
After realizing this, Belgrano created a new flag using the colors that were used by the Criollos during the May Revolution in 1810.
Apparently the original flag was quite different from the current one: it had two vertical stripes, one blue and the other one white.
The flag was first flown, on 27 February 1812, on the Batería Libertad , by the Paraná River.