Black Friday (shopping) corner the gold market. When President Grant learned of this manipulation, he ordered the Treasury to release a large supply of gold, which halted the run and caused prices to drop by eighteen percent. Fortunes were made and lost in a single day, and the president's own brother-in-law, Abel Corbin, was ruined. The earliest known use of "Black Friday" to refer to the day after Thanksgiving occurs in the journal, "Factory Management and Maintenance", for November 1951, and again in 1952. Here it referred to the practice of workers calling in sick on the day after Thanksgiving, in order to
Friday the 13th year being a common year starting on Tuesday (F) (e.g. 2001/02, 2012/13 and 2018/19), or from August to October the following year being a leap year starting on Saturday (BA) (e.g. 1999/2000 and 2027/28). The shortest period that occurs with a Friday the 13th is just one month, from February to March in a common year starting on Thursday (D) (e.g. 2009, 2015 and 2026). Each Gregorian 400-year cycle contains 146,097 days (with 97 leap days) or exactly 20,871 weeks. Therefore, each cycle contains the same pattern of days of the week and thus the same pattern of Fridays that