The eight-hour movement to reduce the working day from 10 to eight hours began after the Civil War. It was a major aim of the National Labor Union, whose first congress met in 1866. By 1868 congress and six states passed an eight-hour legislation. In 1884 the National Federation of Organized Trades and Labor Assemblies decided to call for a general strike on May 1, 1886, to enforce demands for employers to observe the eight-hour day. In 1947, amidst the anti-Communist Cold War hysteria, the US Veterans of Foreign Wars renamed May 1 as « Loyalty Day » and a joint session of Congress later made the pronouncement official.

In many countries, the May 1 holiday was obtained by trade union agitation supported by socialist parties. However, in Germany where such agitation had proved fruitless, it was instituted in 1933 as a gift from Hitler, being promptly followed by the abolition of trade unions. In the United Kingdom, a May Day Bank Holiday was instituted in 1978 for trade unionists to celebrate, but was held on the first Monday in May to minimize the damage to business.

In China, Labor Day was extended to 3 days during the 1990s. The Chinese government made it a seven-day holiday by moving the prior and upcoming weekends together with these three days. This holiday allowed millions of Chinese people to travel during this period. The Chinese government reduced this holiday period down to one day in 2008.

Source: Text: timeanddate.com  Image: Wikipedia, Vienna, Austria, May 1st 2013