This public holiday is always celebrated on 27 February. It is the Dominican Republic's National Day and it commemorates independence from Haiti in 1844.
Following the arrival of Christopher Columbus on Hispaniola on 5 December 1492, the island became the site of the first permanent European settlement in the new world.
The Spanish went on to rule the region known as Spanish Haiti for over 300 years until the Dominican Republic gained independence in 1821. This independence was short lived as shortly afterwards a military invasion by Haiti unified the island of Hispaniola.
In 1844 Juan Pablo Duarte, along with other leaders Francisco del Rosario Sánchez and Matías Ramón Mella created a secret society named 'La Trinitaria' to revolt against the Haitian regime. On February 27, 1844, the Trinitaria declared independence from Haiti.
Carnival is held on 27 February in the Dominican Republic. A festival to mark the start of Lent was a European tradition that made its way to the Americas in the sixteenth century. Carnival is held in other parts of the Caribbean and Latin America in either February or March in the days leading up to the start of Lent. The timing of the declaration of independence was then a good fit with that of carnival.