About Black Friday
Black Friday is the day after Thanksgiving Day in the US (the 4th Thursday of November). Since 1952, it has been regarded as the beginning of the Christmas shopping period, and most retailers open very early (and more recently even overnight) to offer promotional sales. It has been the busiest shopping day of the year since 2005, and stories resurface each year, portraying mass hysteria and not enough stock to meet the demand, creating a state of positive feedback.
It's believed that the phrase Black Friday originated in Philadelphia, where it was used to describe traffic that would occur on the day after Thanksgiving. This dates back to before 1961. More than 20 years on, as the phrase became known as a the point in the year when retailers begin to turn a profit, thus going from being "in the red" to being "in the black".