Calendar Wiki

Messiah’s Calendar is a calendar proposal that has 20 months of 18 days each grouped into 4 seasons, where the last month of a season is longer: It usually has 19 days, but the last month of winter has 20 days in common and 21 days in leap years. The seasons are roughly aligned to the solstices and equinoxes, with the year (and spring) beginning on the Northern vernal equinox (i.e. around Gregorian 20 March).

Months in Messiah‘s Calendar
Spring Summer Fall Winter
Month Days Month Days Month Days Month Days
Unum 18 Sisum 18 Ununum 18 Unsisum 18
Doyum 18 Heptum 18 Undoyum 18 Unheptum 18
Sayum 18 Oktum 18 Unsayum 18 Unoktum 18
Karum 18 Nonum 18 Unkarum 18 Unnonum 18
Pentum 19 Tenum 19 Unpentum 19 Lentum 20 (21)


The calendar uses a 5-day week called penteh which is not aligned with months or seasons, i.e. the calendar is not perennial. The days of the week are called

  1. Festday
  2. Fterday
  3. Firdday
  4. Fothday
  5. Freeday

Every Freeday and the whole pentehs containing a solstice or equinox are considered public holidays.


The day is divided into 20 hours, i.e. 1 Messiah hour is 12 minutes longer than a normal hour. Each Messiah hour contains 100 Messiah minutes of 100 Messiah seconds each, 125 of these seconds equal 54 normal seconds, 2.3(148):1, so a Messiah minute is 43.2 SI seconds or 0.72 minutes long.