What happened to (among other) the eight hour day?

May Day can refer to various labor celebrations conducted on May 1 that commemorate the fight for the eight hour day. May Day in this regard is called International Workers' Day, or Labour Day. The choice of May 1st was a commemoration by the Second International for the people involved in the 1886 Haymarket affair in Chicago, Illinois. As the culmination of three days of labor unrest in the United States, the Haymarket incident was a source of outrage and admiration from people around the globe. In countries other than the United States and Canada, residents sought to make May Day an official holiday and their efforts largely succeeded. For this reason, in most of the world today, May Day has become an international celebration of the social and economic achievements of the labor movement. In some European countries, working people continue to use May Day parades as an opportunity to show disapproval with the government or to protest cuts in social programs. From Wikipedia the_rebel_girl_cover.jpg