World Labour Day

International Workers' Day, also known as Workers' Day or Labour Day in some countries and often referred to as May Day, is a celebration of labourers and the working classes that is promoted by the international labour movement which occurs every year on May Day, an ancient European spring festival.

This holiday is most commonly associated as a commemoration of the achievements of the labour movement. The holiday may also be known as International Worker's Day or May Day and is marked with a public holiday in over 80 countries. 

The first May Day celebrations focused on workers took place on May 1st 1890 after its proclamation by the first international congress of socialist parties in Europe on July 14th 1889 in Paris, France, to dedicate May 1st every year as the "Workers Day of International Unity and Solidarity."

The date was chosen due to events on the other side of the Atlantic. In 1884 the American Federation of Organized Trades and Labor Unions demanded an eight-hour workday, to come in effect as of May 1st 1886. This resulted in the general strike and the Haymarket (in Chicago) Riot of 1886, but eventually also in the official sanction of the eight-hour workday.