It has its origin in France, and it started during the 1800s on that day. Workers through their syndicate revolted against the employers because they were underpaid, had no health insurance and no vacation, and worked day and night. On that day, workers in Gabon are all dressed in uniforms and march in the centre of the town. Some of them march with the work tools, and sometimes they make demonstrations of the way they work. Like we can see the firemen imagining a fire and demonstrating their methods of fighting against it.
People really appreciate it.
After that, people get together to share some drinks and food. They drink a lot of Palm wine, and each family cooks its specialty. Later in the night, people dance to the local rhythms. Everybody feels happy on this holiday.