Since 1901 presidential elections are declared holidays, as mandated by successive versions of the General Elections law.
Since the late 20th century, parliamentary and municipal elections have also been declared public holidays.
Voters directly-elect one mayor and a number of councilmen per municipality. Mayors are elected by a simple majority, while councilmen seats are decided using a system of proportional representation. Mayors and councilmen are elected in separate ballots since 2004.
According to the Constitution, mayors and councilmen have four-year mandates and may be reelected indefinitely. They are elected on the last Sunday of October. The newly elected authorities take office on December 6th of that same year.