a week later…not so ‘good’.

The number 13 has been unlucky for centuries. Some historians peg the superstition to the 13 people who attended the Last Supper (neither Jesus nor Judas came out of that one O.K.), but ancient Babylon’s Code of Hammurabi omits the number 13 in its list of laws, so the superstition dates back to at least 1700 BC. Thirteen is so unlucky, in fact, that in 1881 an organization called the Thirteen Club attempted to improve the number’s reputation. At the first meeting, the members (all 13 of them) walked under ladders to enter a room covered with spilled salt. The club lasted for many years and grew to more than 400 members, including five U.S. Presidents: Chester Arthur, Grover Cleveland, Benjamin Harrison, William McKinley and Theodore Roosevelt. Despite the club’s efforts, triskaidekaphobia (that’s fear of the number 13) flourished; even today, most tall buildings don’t have a 13th Floor.

The number’s association with Friday, however, didn’t take hold until the 20th century. In 1907, eccentric Boston stockbroker Thomas Lawson published a book called Friday the Thirteenth, which told of an evil businessman’s attempt to crash the stock market on the unluckiest day of the month. Thanks to an extensive ad campaign, the book sold well: nearly 28,000 copies within the first week. In 1916 the book was turned into a feature-length silent film.

Wall Street’s superstitions about Friday the 13th continued through 1925, when the New York Times noted that people “would no more buy or sell a share of stock today than they would walk under a ladder or kick a black cat out of their path.” Some stock traders also blamed Black Monday — Oct. 19, 1987 — on the fact that three Fridays fell on the 13th that year. The Stress Management Center and Phobia Institute estimates that $700-$800 million dollars are lost every Friday the 13th because of people’s refusal to travel, purchase major items or conduct business.
….

Read more of this Time.com article here.

staying in time.

SOSIGENES, JULIUS CAESAR and the story of leap year...



Of the author of the Reform of the Calendar, under Julius Caesar in 46 B.C., nothing whatsoever is known except that he was an astronomer of Egypt. He was doubtless an Alexandrian Greek. When Julius resolved on amending the Roman Calendar, which was now 67 days in advance of the true year, he called in the assistance of the astronomer SOSIGENES. Caesar was himself a student of astronomy, and had written a treatise which long remained in use. Using his authority as Supreme Pontiff, and as dictator of the Roman world, he accomplished the reform which is still the calendar of the Christian nations. It was substantially the same as that which had been introduced in Egypt by the Ptolemies nearly two centuries before.

The year 46 B.C., Julius made to consist of 445 days: it was called the year of confusion; but it was more properly the last year of confusion. The reformed year began, not on the 25th of March, but 1st January, 45 B.C. The new year was one of 365 days, with an additional day for every fourth year, in February. The alternate months of the year (January, March, May, July, September, November), were to consist of 31 days: the intervening months were each to be of 30 days (February being 29, except in leap years). This symmetrical arrangement was upset by the vanity of Augustus in 27 B.C., when he gave his own name to the 8th month, then added the day he took from the 9th, and otherwise varied the lengths of the months into their present irregularity.

The Julian year of 365¼ days was too long by 11 minutes 12 seconds. This must have been known to Caesar and to Sosigenes; as more than 100 years before, it had been proved by Hipparchus, whose calculation was within 4 minutes of the truth. Hipparchus had calculated that the error would amount to a day in 300 years; but it seems that the error is more than double and would amount to a day in 128 years. Caesar and his astronomer doubtless considered that the secular error might be left to the future to correct. They could hardly anticipate that it would be binding on Western Europe for 16 centuries, and on Eastern Europe for nearly 20 centuries. Yet so it has proved.

The Julian Calendar, as deformed by Augustus, governed Christendom until 1582, when Pope Gregory XIII, by the advice of Lilio and other astronomers, struck out the ten days then in excess, and reformed the Calendar of Julius by an order, that the last year of each century should be a leap year only when it is exactly divisible by 400. That is to say, 3 leap-years are suppressed in every 4 centuries.

found on: www.usefultrivia.com/biographies/sosigenes