International Fixed Calendar

The International Fixed calendar (also known as the International Perpetual calendar, the Cotsworth plan, the Eastman plan, the 13 Month calendar or the Equal Month calendar) is a proposal for calendar reform providing for a year of 13 months of 28 days each, with one day at the end of each year belonging to no month or week. Though it was never officially adopted in any country, it was the official calendar of the Eastman Kodak Company from 1928 to 1989.Exhibit at George Eastman House, viewed June 2008]

Rules

The calendar year has 13 months each with 28 days plus an extra day at the end of the year not belonging to any month. Each year coincides with the corresponding Gregorian year (and so is a solar calendar).

The months are named the same as for the Gregorian calendar except that a month called "Sol" is inserted between June and July.

In leap years, a leap day, also belonging to no month is inserted after June and before the new month. Common years are 365 days long; leap years are 366 days long.

The first day of each year, January 1, is deemed a Sunday and every subsequent day that belongs to a month is deemed to be in the conventional 7-day week (the days of which go, in order, Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday, followed by Sunday of the next week).

Days that do not belong to a month are deemed to be outside the week and always occur between a day deemed Saturday and a day deemed to be Sunday.

Because each month consists of exactly four weeks, the first day of each month and every seventh day after that for the rest of the month is deemed to be a Sunday, the second day of each month and every seventh day after that for the rest of the month is deemed to be a Monday, and so on. Therefore, each month begins on a Sunday and ends on a Saturday, just like each conventional week.

This causes all months to look like this:

The 13 months and extra days occur on the following Gregorian dates:*These dates are a day earlier in a leap year.

History

The International Fixed Calendar League was founded in 1923 by Moses B. Cotsworth, with offices in London and later in Rochester, New York. It ceased activities in the 1930s.

George Eastman of the Eastman Kodak Company was a fervent supporter of the IFC, and instituted its use at Kodak in 1928, where it remained in use until 1989.

In recent years, there have been attempts to revive the plan.Fact|date=July 2008

The International Perpetual calendar is based on the Positivist Calendar published in 1849 by French philosopher Auguste Comte (1798-1857). Comte based his calendar on Polynesian calendars. The main difference between the International Perpetual calendar and the Positivist calendar is the names Comte gave to months and days. The months in the Positivist calendar were, in order: Moses, Homer, Aristotle, Archimedes, Caesar, St. Paul, Charlemagne, Dante, Gutenberg, Shakespeare, Descartes, Frederick II and Bichat. Every day of the year was likewise named. Positivist weeks, and Positivist months, begin with Monday instead of Sunday. Whereas the Positivist and Sol calendars place the leap day at the end of the leap year, the International Fixed Calendar and the World Calendar both place it after June.

Disadvantages

For the superstitious, a disadvantage to this format is that every month includes a Friday the 13th, and this date occurs thirteen times every year.

Thirteen, being prime, is not evenly divisible, putting all activities currently done on a quarterly basis out of alignment with the months.

Several religious groups oppose any interruption of the seven-weekday sequence.

Date functions in computers would need modifying. The algorithm for determining the day of the week n days from now would be much more complex.

Notes

ee also

* Leap week calendar
* World Calendar

External links

*Article on [http://www.iisg.nl/archives/en/files/i/10751862full.php the International Fixed Calendar League] at "the International Institute of Social History Archives".
* Article about the [http://personal.ecu.edu/mccartyr/eastman.html Cotsworth Calendar of George Eastman] .