Chahar Shanbe Souri, an old habit of Iranians in the last Wednesday night of the persian year. An ancient Iranian festival dating at least back to 1700BCE of the early Zoroastrian era. The festival of fire is a prelude to the ancient "Norooz" festival, which marks the arrival of spring and revival of nature. Norooz, or the New Year's Day in the Iranian calendar. You can see here ( http://www.cais-soas.com/CAIS/Celebrations/fire_festival.htm ) for more information