Calendar and almanac - Arka: One of the Most Developed Conlangs

Gregorian calendar is not used in Atolas. Mel calendar is used in Arbazard instead.

Mel calendar

1 year = 13 months + 1 day (2 days in a leap year)
1 month = 28 days (each of the days is named after the members of Axet (warriors who killed demons in Ardia era))
1 week = 7 days (each of the days is named after the members of Soom (seven demons))

You can check dates on Mel calendar here. This site was programmed by a learner.
You can get Mel Clock here (Windows XP, Vista, 7. .NET Framework needed).