The Bulgar calendar was a calendar system used by the Bulgars, a seminomadic people, originally from Central Asia, who from the 2nd century onwards dwelt in the Eurasian steppes north of the Caucasus and around the banks of river Volga. In 681, part of the Bulgars settled in the Balkan peninsula and established Bulgaria. The Bulgarian calendar is sunny.
RE: Ancient Bulgarian 12 year cyclical calendar