The Armenian calendar is the traditional calendar of Armenia. It was used in Old Armenia at the time before arrival of Christianity. It is a solar calendar based on the same system as the ancient Egyptian model, having an invariant 365-day year with no leap year rule. As a result, the correspondence between it and the Julian calendar slowly changes over time (such as year 769 on AD 1320 January 1, year 770 on AD 1320 December 31, and year 1032 on AD 1582 October 27 = Gregorian November 6). Some references report that the first month of the year, Navasard, corresponds to the start of Spring in the northern hemisphere, but that was only true from the 9th through 10th centuries. The current year, 1461, is the last of the great Armenian cycle of 1,461 wandering years which equal 1,460 Julian years. (See Sothic cycle). Next year, 1462, begins on 24 July 2012 (Gregorian), 11 July (Julian). Year 1 began on 11 July AD 552 (Julian).

The year consists of twelve months of 30 days each, plus five extra days (epagomenê) that belong to no month.

Saint Gregory the Illuminator or Saint Gregory the Enlightener (Armenian: Գրիգոր Լուսաւորիչ translit. Grigor Lusavorich, Greek: Γρηγόριος Φωστήρ or Φωτιστής, Gregorios Phoster or Photistes) (c. 257 – c. 331) is the patron saint and first official head of the Armenian Apostolic Church. He was a religious leader who is credited with converting Armenia from paganism to Christianity, Armenia thus being the first nation to adopt Christianity as its official religion in 301.

Gregory was the son of the Armenian Parthian noblesAnak and Okohe. His father Anak, who was a Prince said to be related to the Arsacid Kings of Armenia or was from the house of Suren-Pahlaw, one of the seven branches of the ruling Arsacid dynasty of Bactria. Anak was charged with assassinating Khosrov II, one of the kings of the Arsacid dynasty and was put to death. Gregory narrowly escaped execution with the help of Sopia and Yevtagh, his caretakers. He was taken to Caesarea in Cappadocia where Sopia and Yevtagh hoped to raise him. Gregory was given to the Christian Holy Father Phirmilianos (Euthalius) to be educated and was brought up as a devout Christian.