Proclamation Day (South Australia), celebration started on the day following Christmas (South Australia)

Proclamation Day commonly refers to the anniversary of the proclamation of government of the province of South Australia, which continues to be celebrated in South Australia on 28 December, although no longer a public holiday. The anniversary of the establishment of self-government on 21 October 1890 was formerly known as Proclamation Day in Western Australia.

Christmas is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world. A liturgical feast central to Christianity, Christmas preparation begins on the First Sunday of Advent and it is followed by Christmastide, which historically in the West lasts twelve days and culminates on Twelfth Night. Christmas Day is a public holiday in many countries, is observed religiously by a majority of Christians, as well as celebrated culturally by many non-Christians, and forms an integral part of the annual holiday season.

South Australia is a state in the southern central part of Australia. With a total land area of 984,321 square kilometres (380,048 sq mi), it is the fourth-largest of Australia's states and territories by area, which includes some of the most arid parts of the continent, and with 1.8 million people, it is the fifth-largest of the states and territories by population. This population is the second-most highly centralised in the nation after Western Australia, with more than 77% of South Australians living in the capital Adelaide or its environs. Other population centres in the state are relatively small; Mount Gambier, the second-largest centre, has a population of 26,878.