International Workers’ Day, also known as Labor Day, is observed worldwide every May 1. This public holiday celebrates the achievements of the labor movement and commemorates the Haymarket affair in Chicago, which occurred on May 1, 1884, when thousands of workers went on strike advocating for an eight-hour workday. The event escalated into violence on May 4, leading to the deaths of several workers and police officers, which solidified May 1 as a day of remembrance for labor rights. International Workers’ Day is particularly significant in socialist and former communist countries, where it is marked by various demonstrations and parades. In the Soviet Union, it was celebrated with large military parades, while in other nations, it often involves family gatherings and picnics. Some countries also associate this day with local labor movement milestones, such as the Philippines, where it commemorates a 1903 rally. However, not all countries observe May 1 as International Workers’ Day; some celebrate it as May Day, a traditional spring holiday.