Dev Diwali, or Dev Deepavali, as the name indicates is the Diwali celebration of the Devas (Demi Gods). In 2012, the date of Dev Diwali is November 28. It is believed that Lord Vishnu returned to Vaikunta, his abode on this day after the Vamana incarnation and visiting King Bali. Another legend has it that Lord Shiva killed the three demons, who were killing the Devas and humans, and destroyed the three cities built by them on this day. The day is also known as Kartik poonam or Karthik Purnima and Tripurari Poornima.
Dev Diwali is observed on the full moon day in the month of Kartik in traditional Hindu calendar and is a major event in Gujarat and other parts of
North India. Tulsi Puja or Tulsi Vivah is a major event on Dev Diwali day for some communities. The famous Akashadeep festival in Varanasi Ghats also comes to an end on the day. The day also marks the end of the Chatur Maas period.
Dev Diwali marks the end of the fortnight of Diwali celebrations and a major event on the day is the lighting of Diyas (lamps) during night after the moon is sighted.