*Zartosht no-diso, or Zarthost no deeso, is an important day of remembrance in the Zoroastrian religion. It is a commemoration of the death anniversary of the prophet Zoroaster, the creator of the Zorastrian faith. It is observed on the 11th day (Khorshed) of the 10th month (Dae). In the seasonal calendar, Zarthost No-Diso falls on December 26.