The day after Thanksgiving in the United States - the 4th Friday in November - has become the traditional starting date for the Christmas shopping season in the U.S. and Canada, marked by promotional sales by major retailers attracting throngs of eager shoppers at early hours seeking the best deals before supplies run out.

Originally used to describe stock market crashes, the term "Black Friday" was first associated with Thanksgiving in the 1960s, referring to the heavy traffic that followed Thanksgiving Day in Philadelphia. But it wasn't until the 1990s that Black Friday began to be widely used as a reference to post-Thanksgiving sales, indicating a day when the retailers went "into the black" and started turning a profit.

The idea that Christmas shopping season begins the day after Thanksgiving has been promoted by retailers and local communities for more than a century with parades like the Macy's Thanksgiving Day Parade in New York and the Toronto Santa Claus Parade that concluded with the appearance of Santa Claus.

It was an unwritten rule among department stores that Christmas advertising would not begin until the parade was over.