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 the last two years, Dutch insurers received reports of an average 7,800 traffic accidents each Friday; but the average figure when the 13th fell on a Friday was just 7,500." In years which begin on the same day of the week and are of the same type (that is, whether they are a common year or leap year), Friday the 13th occurs in the same months. This sequence, given here for 1900–2099, follows a 28-year cycle from 1 March 1900 to 28 February 2100. The months with a Friday the 13th are determined by the Dominical letter (G, F, GF,