Deygan (Dadvah) 1st, Dey 1. This day in the Zoroastrian calendar is known as Deygan (Dadvah) 1st and marks the beginning of the month of Dey. On this date, both the day and the month share the name "Dey," which in Zoroastrian tradition is associated with the celebration of justice and truth, as well as a reminder of ethical values. The Deygan festival is observed by Zoroastrians with family and community gatherings. The occasion emphasizes friendship, solidarity, and acts of goodwill within the Zoroastrian community, and it continues to be celebrated in some regions of Iran and India.