High Quality Content by WIKIPEDIA articles! Diwali (also spelled Devali in certain regions) or Deepavali, popularly known as the "festival of lights," is a festival celebrated between mid-October and mid-December for different reasons. For Hindus, Diwali is one of the most important festivals of the year and is celebrated in families by performing traditional activities together in their homes. For Jains, Diwali marks the attainment of moksha or nirvana by Mahavira in 527 BC.