The ancients were very wise. Divali occurs when the light is very dark at the New Moon in the month where the Sun and its light are at the lowest part of year in Libra. At this time we need more light as we are feeling much emotional darkness around the new moon and spiritual darkness from Sun in Libra. Fight depression with the Light of Divali and get a lift. The holiday starts at sunset on Nov 6th in the West when during the first few hour hours it is auspicious to perform puja. In India, the holiday is Nov 7th this year.