Zoroastrian festivals fall into two broad categories: there are the seven feasts of obligation that included the New Year (No Ruz) and the six gahambars (holy feasts mentioned in Avesta, the Zoroastrians holy book, which formed the framework of the religious year, and had to be observed. There were also other festivals, which was voluntary to observe and not a duty. This second category can be subdivided into major and minor feasts. The major feasts were in honor of great yazatas (benign divinities) of the Zoroastrian pantheon such as the two major deities Mihr, at Mihregan and Tiri at Tiragan. The minor celebrations were created to pay homage to many deities; yazata (eyzads) who symbolized all forces beneficial to humans

The tradition ascribes the foundation of the seven feasts and other celebrations to the prophet himself; but in origin they appear to have been much older. They are pastoral and farming festivals restructured and dedicated to the major deities. With the gahambars, the first feast was celebrated in mid-spring, the second in mid-summer, the third was ‘the feast of bringing in the crop’. The ‘home-coming feast’ (coming of the herds from pasture), was followed by the mid-winter feast and Hamaspathmaedaya, the feast of the feasts celebrated on the last night of the year, before the spring equinox. This feast was eventually incorporated into No Ruz, celebrating the New Year.

The Avestan texts (the Zoroastrians’ holy book) divide the Iranian year into two equal parts or seasons. The first season was summer or ‘Hama’ and the second was winter or ‘Zayana’. The coming of the two seasons was celebrated through No Ruz and Mihregan. The later is the festival dedicated to Mihr Eyzad. It is celebrated on the 16th day of the seventh month (Mihr) at the time of the harvest festivals and the beginning of the winter. It is the second most elaborate celebration after No Ruz. The festival is called ‘Mithrakana’ in Avesta and means ‘belonging to Mithra’.

Mihr has been Mithra in Avesta and Mitrah in Phahlavi. It is the yazata (protector  deity) of the covenant and of loyalty. It has come from the word mei, meaning exchange. In Avesta he is the protector of ‘Payman e Dousti’ (contract of friendship). In modern Persian it means love and kindness. He is the lord of ordeal by fire (walking through fire to prove innocence, story of Siavash in the medieval book Shahnameh) and presides over judgment of the soul at death. Ancient Greeks identified him with Apollo.
This feast was celebrated for 6 days, starting on the 16th day, ‘ the ‘Mihr Ruz’, and ending on the 21st known as ‘Raam Ruz’. The first day was called ‘Mihregan e Khord’ and the last day ‘Mihregan e Bouzorg’ (minor and major Mihregan). The oldest historical record about Mihregan goes back to the Achaemenian times. The Historian, Strabo (66 - 24 BC) has mentioned that the Armenian satrap (governor) presented the Achaemenian king with 20,000 horses at the Mihregan celebrations.

Other Greek sources mention that the kings would dress in purple, dance and drink and this was the only occasion they could get drunk in public. Alcohol, an expensive luxury item, was consumed communally. The celebration is also mentioned in Talmud, the ancient Jewish texts.

The festival is not specific to Iranians and has been celebrated by many cultures in Asia Minor and throughout ancient Mesopotamia. However, what has been celebrated in Iran, with its uniquely Iranian characteristics, is based on the ancient Zoroastrian texts. In Bundahishn (Foundation of Creation), an ancient Zoroastrian text, Mihr day is mentioned as the day when the first male and female, Mashi and Mashiane were created from Gayo-maretan (Kiomarth, the first prototype of all humans). It is also believed that the sun’s first appearance, and Feraydon’s victory over Azydahak (Zahak in Shahnameh) happened on this day. Azydahak is a mythological king in Avesta who wants to destroy all humans and is defeated by the legendary prince, Feraydon who later becomes the king.

According to legend, on this day several Eyzads descended to Earth, helped Feraydon over the next six days to defeat, and eventually imprison Azydahak on the 21st of the month on top of the Damavand Mountain. After this victory, Feraydon ordered all believers to wear ‘Kosti’ (special ceremonial belt Zoroastrians wear) and the prayers ‘Ouj’ were recited for the first time.

In Sasanian times, there were plays and reenactments of this legend accompanied with prayers and songs at the Royal courts. Ancient Iranians believed that it was in Mihr day that humans were given urvan (ravan in modern Persian, meaning soul) and the Earth was enlarged on this day to provide more land for the growing population. Moon (Mah), which was a cold and dark object received light from sun on this day for the first time and began illuminated at night. Mihr is also the protector of the light of the early morning. This light is called havangah in Avestan texts and is referred to as the first ray of light appearing just before dawn. Zoroastrians would get up at this time and pray to Mithra to keep protecting this light against forces of darkness. In mystical Persian literature we know these prayers as ‘Da aye verde sobhgahe’ (prayers of the early morning).

In the ‘Yasht’ section of Avesta (chapters dedicated to prayers) the 10th Yasht is devoted to Mihr and the whole chapter deals with the two most important characteristics attributed to Mithra, truth and courage. Mihr Yasht makes it quite clear that Mihr and the sun are two different entities. Mihr is portrayed as a truthful and brave king with one thousand ears and ten thousand eyes. He is also the protector of warriors, and it has been this aspect of his personality that made this deity popular with the Roman Military and Mithra. This trait also contributed to the eventual evolution of this deity into a major Roman cult and the spread of Mithraism all over Europe.

The celebrations described by the Muslim historians and observers attest to the glory and significance of the occasion. Huge bon fires were set with feasts, songs, music, dancing and prayers. For Zoroastrians today the occasion is a communal one. In the Festival of Mihr; Jasn-e Mihr Eyzad, they all join together for observance and prayer. Until recently, each family gave a contribution of grains, lentils and the like to the fire-temple. Animals were slaughtered by some and the remains were mixed with lentils, herbs and a substantial meal (ash-e khirat) was prepared. Once cooked, the meal is distributed freely to all local people including the non-Zoroastrians. Different kinds of food and delicacies were prepared. These were shared by all including dogs, which were venerated amongst Zoroastrians.

Specific prayers are performed by the mobads (priests) and gifts such as pure oil for the sanctuary lamps, candles and incense are presented to the local shrines. Esphand, a popular incense, is burnt and sweet smelling flowers and herbs are dedicated to the temples. Contrary to the ancient times, there is no rigidly prescribed pattern of behavior for approaching the shrines, but many still touch the doorsill before entering in a graceful gesture of obeisance, while uttering prayers and invocations. IranianMuslims still follow the same procedure once approaching a mosque.

Because of the sanctity of this feast, its ancient communal rites are elaborately celebrated at the ‘Atash Varahram’; the holiest fire in Iran. The greatest observance is the lighting outside this temple of a huge fire just after the sunset. At home, a special table is laid with the fire vase or an incense burner, a copy of the ‘Khordeh Avesta’ (Zoroastrian Holy Book), a mirror for self-reflection, water (the source of life), coins (prosperity), fruits, flowers, sweets, wine and various grains. Elders or priests recite appropriate prayers, especially ‘Mihr Niyaish’ (prayers to Mihr) to signify the occasion. A poem is read to glorify the festival. Food is consumed and those present dance to the tune of music until late in the night.

Music was always a part of all ancient celebrations and the Sassanian court was famous for its musicians and composers. Musical pieces were written for all occasions. Mihregan Khord and Bouzorg are the names of two ‘maghams’ in Persian music. They are mentioned by Nezami, Farabi and other writers in the middle ages, but did not survive and are not in the present-day repertoire of Persian music.

For the ancient Iranians Mihr symbolized truthfulness, bravery and courage. These attributes were re-enforced and venerated through prayers, rituals, feasts, celebrations and acts of charity. Though most modern Iranians have heard about Mihregan, unlike No Ruz, it is not celebrated by all and is mainly regarded as a Zoroastrian festival. In recent years, there has been a revival of this joyful and merry occasion both in Iran and outside and more Iranians are participating in this festival. Also, since school year starts on the 1st day of the Persian month Mihr in Iran, around the 23rd of September Mihregan is celebrated as a time to celebrate learning and knowledge in order to make the festival more acceptable with the Islamic authorities.