International Workers' Day, also known as Labour Day in some places, is a celebration of labourers and the working classes that is promoted by the international labour movement (as well as Anarchists, Socialists, and Communists) and occurs every year on May Day, May 1.
Although in Canada, we celebrate Labour Day on the first Monday of each September, International Workers’ Day is a day recognized by unions and leftists. May 1 was chosen to be International Workers' Day in order to commemorate the May 4, 1886 Haymarket affair in Chicago, when a general strike for the eight-hour workday turned ugly and four demonstrators were killed by police. But it was in Canada, where the movement started.
The “Nine-Hour Movement” began in Hamilton, Ontario, then spread to Toronto in 1869. By 1872 almost all union demands included the 54-hour work week and it was Toronto printers who pioneered the nine-hour work day, which later spread to Chicago and New York at the turn of the century.
It seems strange now, but it was common place during the Industrial Revolution for workers to put in as many as 16 hours a day, six days a week, often in unsafe conditions and often the workers were children. Around the world, most industrialized countries adopted the eight-hour work day throughout the late 1800s and early 1900s. New Zealand was the first to do this in a variety of trades in the 1840s and 1850s. Mexico even included the eight-hour workday in its constitution in 1917.
Today in Canada the general standard for hours worked is eight hours per day or 40 hours per week, however there are certain exceptions to this depending on profession and mutual agreement between the worker and employer.