If you are traveling in Latin America on the first day of May, you can expect to find banks, government offices, stores, post offices and businesses closed for the day as people celebrate the Día Internacional Del Trabajo with parades, demonstrations and other symbols of solidarity with the worker.
Venezuela celebrated Día Internacional del Trabajo for the first time on May 1, 1936. Day of the Worker, or May Day, had already been established in Europe, and would shortly sweep across the Latin American countries.
The communist and socialist countries embraced the day, and over time, May Day became associated with those political systems in many non-English speaking countries.
"In Paris in 1889 the International Working Men's Association (the First International) declared May 1st an international working class holiday in commemoration of the Haymarket Martyrs. The red flag became the symbol of the blood of working class martyrs in their battle for workers rights."
Who were the Haymarket Martyrs? They are all but ignored in the history of the United States, who moved the May Day labor celebrations to September. The first Monday in September is now the Labor Day holiday, but it has very little to do with the reason for a working man's holiday. This history is detailed in May Day - the Real Labor Day.
Long before May Day, The Workers' Day, born in the struggle for the eight-hour day came to be, the first of May was a traditional day of feasting, celebrating spring, fertility, romance and more.
The Pagan Origins of May Day asks "Why did the Labour Movement choose May Day as International Labour Day? It's more that May Day chose the Labour Movement. Unlike Easter, Whitsun or Christmas, May Day is the one festival of the year for which there is no significant church service. Because of this it has always been a strong secular festival, particularly among working people who in previous centuries would take the day off to celebrate it as a holiday, often clandestinely without the support of their employer. It was a popular custom, in the proper sense of the word - a people's day - so it was naturally identified with the Labour and socialist movements and by the twentieth century it was firmly rooted as part of the socialist calendar."
So now you know why everything shuts down on May 1. It's a good idea to play it safe that day and stay away from parades and rallies that might prove explosive.
Buen viage! Boa viagem!