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 are on the 13th. The 13th day of the month is slightly more likely to be a Friday than any other day of the week. On average, there is a Friday the 13th once every 212.35 days, whereas Thursday the 13th occurs only once every 213.59 days. In the 2010s there were three Friday the 13ths in 2012 and 2015, and two in 2013, 2017 and 2018. There will also be two in 2019 and 2020. In the 2020s, there will be three F13's in 2026, and two in 2020, 2023, 2024, and 2029. The rest of years have at