Labour Day in Australia is observed on different dates across various states and territories, with the Australian Capital Territory, South Australia, and New South Wales celebrating it on the first Monday in October. The holiday commemorates the achievements of the labor union movement, particularly the establishment of the eight-hour workday. The origins of Labour Day date back to the mid-19th century, when laborers worked up to 14 hours a day without sick or holiday leave. Notably, on August 18, 1855, the Sydney Stonemasons Society initiated a successful strike for an eight-hour workday, leading to celebrations of their victory. In Melbourne, workers also marched on April 21, 1856, demanding the same rights, which they achieved without loss of pay. Over the years, the eight-hour day became a national standard, culminating in the approval of a 40-hour five-day workweek in 1948. Other states, such as Western Australia, Tasmania, and Victoria, celebrate Labour Day on the first Monday of March, while Queensland and the Northern Territory observe it on the first Monday in May.