De jure and de facto, Ardenjost uses two calendars: Gregorian and Catameilan.
- Jendun (compare Jend Arder Kons = First other Moon)
- Pratzun (compare Prett Arder Kons = Second other Moon)
- Lanjun (compare Klemt Arder Kons = Third other Moon)
- Nelderdoun (compare Neler Arder Kons = Fourth other Moon)
- Funderdoun (compare Fuger Arder Kons = Fifth other Moon)
- Kesterdoun (compare Kjeser Arder Kons = Sixth other Moon)
- Hiuderdoun (compare Zifter Arder Kons = Seventh other Moon)
- Bifintar (compare Bifide = to hallow)
Bifintar has 34 days every year. Malit has 31 days on normal years, but 32 on leap years.
Every other month has always 30 days.
The calendar starts from April 3rd, 47 BC, when, according to Catameilan teachings, Sattama left this world/universe to save others. In Sonnend language, dates after this are written as 'MD' (Manja Daremmusy, After finishing the job), and dates before 0 are written as 'EEE' (Ema ela erkiji, Before anything in our minds)