Calendar Wiki

The Saeculum Calendar is constructed for a period of 108 years or 6 consequtive saros periods. There are no leap days, however leap months every 6 years and one time in the middle of the saeculum. There are three extra months during the first saeculum where adoptions can be made.


  • The calendar shall consist of a period of 6 consecutive saros periods.
  • Each year consists of 73 months à 30 days. After a period of three times 12 months there follows one Janus month after which again three times 12 months follow.
  • After 9 years there shall be three additional months, called saeculum-months or great-months; one month à 31 days followed by one à 27 days and any other correction time followed by one à 31 days.
  • Besides the years, mainly the saeculum-periods shall be counted; so saeculum 1, saeculum 2. Also saeculum 2 year 4 would be the adequate year count. A full date would be written 2/4/32/21 (4/32/21) for saeculum 2, year 4, month 32, day 21, where the weekday would be unnecessary. Another way would be 2/4/Ur2/Io3, or Ur2/Io3 for daily dates.


  • Months 1-12 are named after the zodiacs, standing for the old empires. The zodiacs shall be adopted to the zodiac on the first day of the month.
  • Months 13-24 are called in roman fashion, i.e. by Roman gods and festivities. The circle shall be always in this way that Invictus is the month of the winter solstice.
  • Months 25-36  resemble the medieval time, the Franconian empire, using German archangels and harvest-times. The knospenmond shall always on the beginning of spring.
  • The 37th month shall be called Janus month.
  • The following 36 months are named in the same way, however the three circles are laid oppositely. To differentiate them from the months in the first circle one can mark them with the prefix re-, so March and Remarch.


  • During the first saeculum-months, the day, hour, minute and second shall be adopted on its de-facto time, where the 27 extra days won’t be necessary afterwards. This can just be corrected with the new time model in place. In case the time model would not be adopted, the saeculum-month with 27 days shall be used for the century correction of the Gregorian calendar.
  • The calendar started with 2016-09-09T00:00Z, the day of the rediscovery of Ambrosia, where the first month is Janus, and afterwards adequate zodiac. An alternate starting date might be possible.


There is an online version of the calendar by its inventor.