When did Saint-Domingue become Haiti?

Saint-Domingue became Haiti on January 1, 1803. On this day, rebels led by Jean-Jacques Dessalines declared their independence from France. This event was the culmination of a long and bloody struggle against the French colonial leaders, one which had frequently taken the form of a civil war fought not just along racial lines, but with free people of color sometimes siding with whites. Its initial leader, Toussaint L'Ouverture, was imprisoned in Europe at this point, and would die just a few months later. Dessalines declared independence after defeating a French force sent by Napoleon Bonaparte to recover the island several years after L'Ouverture had concluded a peace agreement with the French revolutionary government. With this declaration, Haiti became the second independent republic in the Western hemisphere, after the United States. This revolution, not simply a by-product of the French Revolution, had global ramifications, not least because it ran counter to many racial assumptions. The idea that people of African origin could establish a free government was anathema to proslavery ideology.
https://www.history.com/this-day-in-history/haitian-independence-proclaimed