Zartosht No-Diso

On this important day (Zartosht No-Diso), Zoroastrians mark the death anniversary of the prophet Zoroaster, founder of their faith. Falling on the 10th of the month of Dae, it is a solemn occasion. Believers attend special services at the fire temple with prayers, lectures and discussions on the prophet’s life and works.

Sourced from https://theguibordcenter.org/zoroastrian-holy-days-and-observances/