Black Friday

"Black Friday, the day after Thanksgiving in the United States, marks the beginning of the traditional Christmas shopping season, although retailers often decorate for the Christmas season weeks before-hand. Many retailers open very early (typically 5 A.M.) and offer doorbuster deals to draw people to their stores. Although Black Friday has served as the unofficial beginning of the Christmas season for decades, the term has been traced back only to the 1970s and did not achieve widespread popularity until about 2002."
http://en.wikipedia.org/wiki/Black_Friday_(shopping

I must admit I find the fascinating as we do not have a "black Friday" in Canada

Urban Dictionary:
The day after Thanksgiving in the U.S. It's traditionally the busiest shopping day of the year (and sometimes considered to be the beginning of the Christmas season). A.K.A.: Green Friday

"I'm holding out on buying my Christmas gifts this year until black friday rolls around, so I can get the best deals."
http://www.urbandictionary.com/define.php?term=black+friday