And on Oct. 9, 1582
no one was born.
Further, no couple
was married on Oct. 12.
A calendar page from October 1582 can best–first–response to this.
For that and more, please use the DOOR.
Sun Mon Tue Wed Thur Fri Sat
1 2 3 4 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
Out with the Julian calendar
In with the Gregorian calendar
Okay, so what happened here? Well, in the month of October of A.D. 1582, 10 days of the month got thrown out. This was the result of an astronomer’s figuring and a pope’s acting. The calendar year was slowing down so it had to jump ahead 10 days to catch up to the annual solar years that were taking place. Confused? …And still interested? If so, we’ve more for you below the line¹.
But before you do that, note that the 7-day sequence of the days of the week had not been interrupted.
¹ In the 16th century, most of Europe was using the Julian calendar, created in the first century B.C. The Julian calendar operated on a four-year-cycle, with 365 days in the standard year and a 366-day year every fourth year.
The 365 1/4-day year came very close to approximating the solar year, the length of time it takes for the Earth to revolve completely around the sun (about 365.2424 days, according to The Galileo Project). However, over the span of centuries, the difference (about 11 minutes, 14 seconds) added up, and the calendar began to become noticeably inaccurate.
The vernal equinox, which typically occurs on March 20, was occurring about 10 days later on the calendar. This had particular significance for the Catholic Church, which celebrated Easter on the first full moon after the equinox (fixed by the church at March 21), and set other religious dates depending on the date of Easter. “An error in the equinox thus introduced numerous errors in the entire religious calendar,” explains The Galileo Project.
Christopher Clavius, a Jesuit mathematician and astronomer, led a commission that proposed the Julian calendar be changed to better approximate the solar year. The solution was to drop a leap day three times in a 400-year cycle; every year divisible by 100, but not by 400, would lose its scheduled leap day. The result was a 365.2425-day year, nearly identical to the average solar year of 365.2424 days.
In order to restore March 20 or 21 as the day of the lunar equinox, Clavius recommended that 10 days be skipped. Pope Gregory XIII issued an order that Oct. 5-Oct. 14 be dropped from the calendar in 1582.
The Catholic countries in Europe adopted the order immediately, while most Protestant adopted in years later. Russia, Greece, and numerous other countries in Eastern Europe continued using the Julian calendar into the 20th century.