The First Day of May is celebrated as the International Workers' Day by workers all around the world, including Indonesia. In this connection, I would like to quote an article in Wikipedia as follows :
The International Workers' Day is the commemoration of the Haymarket Massacre in Chicago, U.S.A. in 1886, when Chicago Police fired on workers during a general strike for the eight hour day, killing a dozen demonstrators.
In 1889, a meeting in Paris for the centennial of the French Revolution and the Exposition Universelle, called for international demonstrations on the 1890 anniversary of the Chicago protests. It was so successful that May Day was formally recognized as an annual event in 1891. The May Day Riots of 1894 and May Day Riots of 1919 occurred subsequently. In 1904, the International Socialist Conference meeting in Amsterdam called on "all Social Democratic Party organizations and trade unions of all countries to demonstrate energetically on May First for the legal establishment of the 8-hour day, for the class demands of the proletariat, and for universal peace." As the most effective way of demonstrating was by striking, the congress made it "mandatory upon the proletarian organizations of all countries to stop work on May 1, wherever it is possible without injury to the workers."
Through all this turmoil in the northern hemisphere, the Stonemasons Society in the then colony of Victoria, now the State of Victoria in Australia led the battle for the 8 Hour Day, the most dramatic achievement of the early trade Union Movement. By 1856 Australian workers were benefiting from the results of a decision by the Collingwood Branch of the Stonemasons Society of Victoria. The same year it was recognized in New South Wales, followed by Queensland in 1858 and South Australia in 1873. A memorial statue with the numerals 888, representing 8 hours of work, 8 hours of recreation, and 8 hours of rest, sits on the corner of Lygon Street and Victoria Parade in Melbourne, Australia to this day.
May Day has long been a focal point for demonstrations by Socialist, Communist, and Anarchist groups. In some circles, bonfires are lit in commemoration of the Haymarket martyrs, usually right as the First day of May begins. It has also seen right-wing massacres of participants as in the Taksim Square massacre of 1977 in Turkey.
Due to its status as a celebration of the efforts of workers and the socialist movement, May Day is an important official holiday in Communist countries such as the People's Republic of China, Cuba, and the former Soviet Union. May Day celebrations typically feature elaborate popular and military parades in these countries.
In countries other than the United States and Canada, resident working classes sought to make May Day an official holiday and their efforts largely succeeded. For this reason, in most of the world today, May Day is marked by massive street rallies led by workers, their trade unions, anarchists and various communist and socialist parties.
In the United States, however, the official Federal holiday for the "working man" is Labor Day in September. This day was promoted by the Central Labor Union and the Knights of Labor organized the first parade in New York City. The first Labor Day celebration was held on September 5, 1882, and was organized by the Knights of Labor. The Knights began holding it every year and called for it to be a national holiday, but this was opposed by other labor unions who wanted it held on May Day (as it is everywhere else in the world). After the Haymarket Square riot in May, 1886, President Cleveland feared that commemorating Labor Day on May 1 could become an opportunity to commemorate the riots. Thus he moved in 1887 to support the Labor Day that the Knights supported.
May Day celebrations around the World :
May 1 is a national holiday in Albania, Argentina, Aruba, Austria, Bangladesh, Belgium, Bolivia, Bosnia, Brazil, Bulgaria, Cameroon, Chile, Colombia, Costa Rica, China, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Dominican Republic, Ecuador, Egypt, Finland, France, Germany, Greece, Guatemala, Haiti, Hong Kong, Hungary, Iceland, India, Italy, Ivory Coast, Jordan, Kenya, Latvia, Lithuania, Lebanon,Macedonia, Malaysia, Malta, Mauritius, Mexico, Morocco, Myanmar (Burma), Nigeria, North Korea, Norway, Pakistan, Paraguay, Peru, Poland, the Philippines (spelled as "Labor Day"), Portugal, Romania, Russian Federation, Singapore, Slovakia, Slovenia, South Korea, South Africa, Spain, Sri Lanka, Serbia, Sweden, Syria, Thailand, Turkey, Ukraine, Uruguay, Venezuela, Vietnam, Zambia, and Zimbabwe.