Welsh manufacturer and social reformer Robert Owen formulates the slogan that would become the symbol of the labour movement for decades.
The British parliament passes legislation limiting working hours for children in textile factories, an early step in labour law.
A strike for the eight-hour workday in Chicago escalates into violence after a bomb is thrown during a labor rally.
Socialist parties and trade unions united in the Second International choose May 1st as the annual international day of action for the eight-hour workday.
New Zealand is among the first countries to enshrine the eight-hour working day in law, partly thanks to early labour legislation.
Ford shortens the working day to eight hours while simultaneously raising wages, in the belief that this increases productivity and worker loyalty.
After the end of the First World War, the International Labour Organization is established, whose first convention lays down the eight-hour working day internationally.
The young Soviet state incorporates the eight-hour workday into its labor legislation as part of the revolutionary reforms.
Under British colonial rule, the eight-hour workday is enshrined in law in Indian factory legislation.
France consolidates the eight-hour workday into national legislation, as the culmination of decades of union struggle in Western Europe.
On May 1, 1886, tens of thousands of American workers went on strike for an eight-hour workday. A few days later, on May 4, a bomb exploded near police during a protest rally at Haymarket Square, after which shots were fired and several people died. The affair led to controversial trials against anarchist leaders and later became the reason for the international celebration of May 1 as Labor Day.