Calendar reform

Calendar designs are calendars that were designed for political, religious, astrological, astronomical, literary or economic reasons or merely as a thought experiment and were officially used only for a short time or were only proposed to improve the commonly used (mostly Gregorian) calendar, supplement or replace.

Criticism of the Gregorian calendar

The Gregorian calendar is the basis of the international standard ISO 8601 and is used worldwide, partly However, parallel to traditional local systems. Except for the switching rule it corresponds to the older Julian calendar. Nevertheless, there are some historically or systematically related weaknesses in relation to various application areas, which are criticized accordingly.

• The months are 28 or 29, 30 and 31 days long unevenly.
• The short and long months are irregularly distributed over the year, so that the quarters are unequal in length.
• Neither years, half- years, quarters or months correspond with the seven-day weekly cycle, so there are 14 different calendar years (both 7 versions of the common years and leap year ). Therefore, annual holidays etc. are available in the following year either on a different day or on a different date.
• The numbering of years, that is, the determination of the epoch is determined Christian and therefore not religiously neutral.
• The leap years are not regularly distributed over the 400 - year cycle.
• The average year, is slightly longer than the astronomical year 365.2425 days, whereby there are different possibilities to determine it.
• The months do not coincide with the phases of the moon.
• Names for weekdays and months are based on outdated concepts in many languages ​​, for example German: January, March, May and June go back to the Roman deities.
• July and August are named after Roman emperors.
• September, October, November and December are based on the Latin ordinal numbers 7-10 instead of 9-12 because the month before counting began in March.
• Tuesday, Thursday and Friday have their names of Germanic deities.
• Although Wednesday is in the middle of the five-day work week and the beginning of the Christian on Sunday week, but not the beginning on Monday civilian seven -day week.

Requirements of a globally applicable culture-neutral Calendar

From different sides, different demands are placed on a new calendar, which contradict each other partially. Some are radical schematic or purely aesthetic in nature, others are more conservative in order to ensure acceptance and compatibility with the previous or religious festival calendars.

Comparison of some calendar designs

The Gregorian calendar are compared based on some criteria, the two temporarily already implemented reform calendar from the First French Republic and the Soviet Union as well as several proposed calendar drafts.

The weekly calendar according to ISO 8601 itself contains no months, but corresponds to the Gregorian calendar, but there are various proposals, the newly divide 52 weeks (plus shift week) in 12 or 13 months. Then, the data refer in brackets.