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. For other uses, see Calendar (disambiguation) A page from the Hindu calendar 1871–1872. ... Calendar reform is any proposed reform of a calendar. ... A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Look up Month in Wiktionary, the free dictionary. ... Look up day in Wiktionary, the free dictionary. ... Look up day in Wiktionary, the free dictionary. ... For more details on each day of the week, see days of the week. ...

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. For the calendar of religious holidays and periods, see liturgical year. ...

The months are named the same as for the Gregorian calendar except that a month called Sol is inserted between June and July. For the calendar of religious holidays and periods, see liturgical year. ...

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. For the 1921 film starring Fatty Arbuckle, see Leap Year (film). ... A leap year (or intercalary year) is a year containing an extra day or month in order to keep the calendar year in sync with an astronomical or seasonal year. ... A common year is a year that is common calendar year. ...

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). is the 1st day of the year in the Gregorian calendar. ...

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. For more details on each day of the week, see days of the week. ...

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, with offices in London and in Rochester, New York, ceased activities in the 1930s. In recent years, there have been attempts to revive the plan. This article is about the capital of England and the United Kingdom. ... This article is about the city of Rochester in Monroe County. ... This article is about the state. ... Year 1930 (MCMXXX) was a common year starting on Wednesday (link will display 1930 calendar) of the Gregorian calendar. ...

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. The positivist calendar was a proposal for calendar reform proposed by Auguste Comte in 1849. ... Year 1849 (MDCCCXLIX) was a common year starting on Monday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ... Auguste Comte (full name: Isidore Marie Auguste François Xavier Comte; January 17, 1798 - September 5, 1857) was a French thinker who coined the term sociology. ... Moses with the Tablets, 1659, by Rembrandt This article is about the Biblical figure. ... This article is about the Greek poet Homer and the works attributed to him. ... For other uses, see Aristotle (disambiguation). ... For other uses, see Archimedes (disambiguation). ... For other uses, see Julius Caesar (disambiguation). ... Paul of Tarsus (b. ... For other uses, see Charlemagne (disambiguation). ... DANTE is also a digital audio network. ... This article is about the inventor of printing in Europe; for other uses, see Guttenberg (disambiguation) and Gutenberg. ... Shakespeare redirects here. ... René Descartes René Descartes (IPA: , March 31, 1596 – February 11, 1650), also known as Cartesius, worked as a philosopher and mathematician. ... See: Frederick II, Holy Roman Emperor (1194-1250, king 1211/12-1250, emperor since 1220) Frederick II of Austria (?-1246, duke of Austria 1230-1246) Frederick II of Sicily (1272-1337) - who called himself Frederick III - see the article for details. ... Marie François Xavier Bichat Marie François Xavier Bichat (November 14, 1771 - July 22, 1802), French anatomist and physiologist, was born at Thoirette (Jura). ... For more details on each day of the week, see days of the week. ... In Egyptian mythology, Month is an alternate spelling for Menthu. ...

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. This article is about the superstition. ...

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.

See also

• Leap week calendar
• World Calendar

The leap week calendar is a reformed calendar system with a whole number of weeks every year, and with every year starting on the same weekday. ... The World Calendar is a proposed reform of the Gregorian calendar created by Elisabeth Achelis of Brooklyn, New York in 1930. ...

External links

• Article on the International Fixed Calendar League at the International Institute of Social History Archives.
• Article about the Cotsworth Calendar of George Eastman.