Diwali is the five-day festival of lights, celebrated by millions of Hindus, Sikhs and Jains across the world. The festival, which coincides with the Hindu New Year, celebrates new beginnings and the triumph of good over evil and light over darkness.Diwali is the five-day festival of lights, celebrated by millions of Hindus, Sikhs and Jains across the world. The festival, which coincides with the Hindu New Year, celebrates new beginnings and the triumph of good over evil and light over darkness.