International Labor Day, also known as May 1 International Labor Day, Labor Day, and International Demonstration Day, is the Labor Day of most countries in the world. To commemorate the hay market incident in 1886 when Chicago laborers in the United States fought for an eight-hour work system and were suppressed by the police.
May 1 is a legal holiday in many countries in the world, and in most cases it is "Labor Day", "International Workers' Day" or similar names. Although some countries celebrate Labor Day on other dates, for example, the United States and Canada celebrate Labor Day on the first Monday in September.