The unofficial end of summer, this day of barbecues and parades originally recognized the accomplishments of the labor movement, which include the 8 hour work day and the 40 hour work week. More than 80 countries observe International Workers Day on May 1 instead. Since that date was proposed by the Second International of communist and socialist parties, that name never caught on in the United States. Even so, it was intended to commemorate an American event, the 1886 Haymarket affair in Chicago, a protest for an 8 hour work day that was peaceful until someone threw a bomb.