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        Science | Astronomy Terms

Calendar Reform

As far as its relation to the seasons is concerned, the Gregorian calendar is very nearly perfect. With 97 years out of every 400 being leap years, the average length of the year is about 26 seconds more than that of the solar yeara difference of one day every 3,323 years. It has been suggested that the year 4000 and future century years that can be divided by 4,000 be made ordinary (365-day) years rather than leap years. If this suggestion were followed, 20,000 years would pass before the calendar was again a day too long.

However, the Gregorian calendar does have shortcomings. The months vary in length, ranging from 28 to 31 days. Furthermore, the six months from January through June have 181 or 182 days, while the second six-month period is 184 days long. The quarterly divisions of the months are also unequalthe first quarter has 90 or 91 days, the second quarter 91 days, and the third and fourth quarters 92 days each. Finally, neither the year nor the months (except February, in common years) can be exactly divided into weeks. These irregular divisions are particularly annoying in the world of business.

Many suggestions have been made for reforming the calendar. These have been most seriously considered:

The 13-month Calendar

This is a revised version of a calendar first proposed in 1849 by the French philosopher Auguste Comte. It divides the year into 13 months of 28 days each. The extra month, named Sol, comes between June and July. Since this system gives a year of only 364 days, a special day ("Year End Day) is placed between December 28 and January 1. This day belongs to no week or month. Every four years a similar Leap Year Day is inserted between June and Sol. Each month begins on Sunday and ends on Saturday. This plan is also called the international fixed calendar.

The World Calendar

This calendar, also first proposed in the 19th century, did not receive much attention until after World War I. It keeps the 12-month scheme. The first month of each quarter contains 31 days and the other two months 30 days each. Each quarter begins on Sunday, and each has the same number of working days. The Year End Day is placed between December and January, and the Leap Year Day between June and July. These two days would be holidays outside the seven-day week, as in the 13-month calendar.

The Perpetual Calendar

First proposed in 1919 by Willard E. Edwards, this calendar is a 12-month system similar to the World Calendar except for certain details. Each quarter has 91 days; the first two months are 30 clays long, the third is 31. The week begins on Monday instead of Sunday, and each quarter begins on a Monday and ends on a Sunday. The extra day each year is New. Year's Day, which falls between December 31 and January 1.