Mehrgan festival in Paris

Mehregan (also known as Jashan-e Mehr) usually occurs in the first week of October depending on the alignment of both the Solar Hijri calendar used officially and the Fasli calendar used by many Zoroastrians. This alignment occurs when the day of Mehr occurs in the month of Mehr according to these calendars. It is a multi-faceted holy festival that celebrates the Yazata Mithra (known also as Mihr or Mehr), our divinity and hypostatis of promises, friendship, relationships, and covenants who appears in most Zoroastrian scriptures from the Gathas of Zarathushtra onwards, along with the commemoration of other stories important to the Zoroastrian tradition. It is also the Zoroastrian equivalent of the Autumn Equinox which traditionally occurs September 21/22 in the Gregorian calendar.