Black Friday is the Friday following Thanksgiving Day in the United States, which is the beginning of the traditional Christmas shopping season. The term dates back to at least 1966, although its usage was primarily on the East coast. The term has become more common in other parts of the country since 2000. Because Thanksgiving falls on the fourth Thursday in November in the United States, Black Friday occurs between the 23rd and the 29th of November. According to Reuters, in 2007 135 million people participated in the Black Friday shopping rush.

Black Friday is not an official holiday, but many employees have the day off as part of the Thanksgiving holiday (with the exceptions of those employed in retailing, health care, and banking), which increases the number of potential shoppers. Retailers often decorate for the Christmas and holiday season weeks beforehand. Many retailers open extremely early, with most of the retailers typically opening at 5AM or even earlier. Some of the larger retailers (depending on the location) such as Sears, Best Buy, Macy's, Toys "R" Us, and Walmart have been reported to open as early as midnight on the start of Black Friday in localized areas and remain open for 24 hours throughout the day until midnight the following Saturday. Upon opening, retailers offer doorbuster deals and loss leaders to draw people to their stores. Although Black Friday, as the first shopping day after Thanksgiving, has served as the unofficial beginning of the Christmas season at least since the start of the modern Macy's Thanksgiving Day Parade in 1924, the term "Black Friday" has been traced back only to the 1960s.

The term "Black Friday" originated in Philadelphia in reference to the heavy traffic on that day . More recently, merchants and the media have used it instead to refer to the beginning of the period in which retailers go from being in the red to being in the black.

在美国，感恩节后的礼拜五被称为“黑色的礼拜五”。人们从这一天开始进行购买传统的圣诞礼物。这个“黑色的礼拜五”至少从1966年就开始用了，当初只是在美国的东部流行，到2000年，这个称呼已经在全美国变得很通行了。

根据美国现在的法律，感恩节是在十一月的的第四个礼拜的礼拜四，所以“黑色的礼拜五”就在十一月的23日到29日之间。根据路透社在2007年的报道，全美国有一万三千五百万人在“黑色的礼拜五”那一天，涌到商场购货。

"黑色的礼拜五”不是一个官方的假日，但是很多公司和企业，除了零售店的售货员、医务工作人员和某些银行的工作人员不放假以外，都把这一天与感恩节连在一起作为假日让员工休 一个超长的周末。这样一来，在商场上购货的大军就显得更加壮观了。商场为了这个强烈的购物风，在几周以前就把商场打扮的充满着感恩节、圣诞节和新年的节日气氛 ，货物摆得琳琅满目。在“黑色的礼拜五”，商店的门都特别特别早地开了；绝大部分的商店在清晨五点就开门了，有的甚至开得更早。美国的大商场和大百货店，比如Sears和Macy's、大电器商店Best Buy、超级玩具店Toy "R" Us、和沃尔玛超级市场，在“黑色的礼拜五”刚一开始的半夜凌晨就开门了，而且整天二十四小时开门，全天候地服务，直到礼拜六的到来。当然这些也是随着地区不同而有所变化的，并非千篇一律。

在商场开门之前，他们做了很多广告，希望顾客们在被广告吸引到这个商场的同时也购买其他没有做广告的商品。让人们感到，人已经到了这里，反正我要买这个商品，那我就在这里买了吧。虽然“黑色的礼拜五”是感恩节后的第一个购货日，大家也认为是圣诞季节的开始，尤其是从1924年开始，Macy's的纽约总部，在每年的感恩节那一天都会组织有很多彩车的游行，给人们带来了感恩节和圣诞节的节日气氛，但是人们到上个世纪的六十年代才开始使用“黑色的礼拜五”这个名词。

“黑色的礼拜五”这个名词最早是费城用来描写交通严重阻塞的那一天。但是现在，商家和媒体有了一个不同的概念。因为零售商从年初到感恩节那一天的生意都不是那么的好，在他们的营业账簿里显示的常常都是红色的“赤字”，他们希望在“黑色的礼拜五”那一天，他们可以把大量的货物卖出去，从此他们的账簿里显示的数字从红色的“赤字”变为黑色的赢利。这就是“黑色的礼拜五”这个名词的来源。