Hours of Work (Industry) Convention, 1919 is an International Labour Organization Convention.
It was established in 1919:
Having decided upon the adoption of certain proposals with regard to the "application of the principle of the 8-hour working day or of the 48-hours week"...
As of 2013, the convention had been ratified by 52 states. Of these ratifying states, one—New Zealand—has subsequently denounced the treaty.