It falls on November or December of the Gregorian calendar and is also known as Tripurari Purnima or Deva-Deepavali, the gods's festival of lights.

The killing of the demon(s) and destruction of his/their cities with a single arrow by Shiva overjoyed the gods, and they declared the day as a festival of illuminations.

[2] Kartika Purnima is also celebrated as the manifestation day of Matsya, the god Vishnu's fish incarnation (avatar) and Vrinda, the personification of the tulasi.

[3] In the Brahma Vaivarta Purana, Tulasi is a gopi cursed to be born on earth as a princess and marry Shankacuda, an asura.

[4] In Southern India, Kartika Purnima is also celebrated as the birthday of Kartikeya, the god of war and elder son of Shiva.

[1] Underhill believes that the origins of this festival may lie in ancient times, when a sacrifice called Shakamedhah was performed to attain victory over enemies.

[5] The festival has even more significance when the day falls in the nakshatra (lunar mansion) of Krittika and is then called Maha Kartika.

Any philanthropic act on this day is supposed to bring benefits and blessings equal to the performing of ten yajnas.

[6] Kartika Purnima is closely associated with Prabodhini Ekadashi, which marks the end of the chaturmasya, a four-month period when Vishnu is believed to sleep.

[9][10][11][12] A ritual bath at a tirtha (a sacred water body like a lake or river) at a pilgrimage centre is prescribed on Kartika Purnima.

[8] In Odisha, on Kartika Purnima, people celebrate Boita Bandana (Odia: ବୋଇତ ବନ୍ଦାଣ boita bandāṇa), in memory of ancient maritime trades via Kalinga[14] by heading for the nearest water body to set afloat miniature boats, originally made out of banana stem and coconut stick, lit with Deepak (lamps), fabric, betel leaves.

The festival is a mass commemoration of the state's glorious maritime history when it was known as Kalinga and tradesmen and mariners known as sadhabas traveled on boitas to trade with distant island nations that share borders with the Bay of Bengal like Indonesia, Java, Sumatra and Bali.

The day after Kartika Purnima is called Chhada Khai when the non-vegetarian people can again start their normal diet.

[16] Thousands of Jain pilgrims flock to the foothills of Shatrunjay hills of Palitana taluka on the day of Kartika Purnima to undertake the auspicious yatra (journey).

Also known as the Shri Shantrunjay Teerth Yatra, this walk is an important religious event in the life of a Jain devotee, who covers 216 km of rough mountainous terrain on foot to worship at the Adinath temple atop the hill.

[2] The day of Kartika Purnima is very significant in Jainism.Jains believe that Adinath, the first tirthankara, sanctified the hills by visiting it to deliver his first sermon.

[17] Sikh contemporary sources rather mention Vaisakh (Mid April) as birth month of Guru Nanak.

[18] This was done to prevent Sikhs from joining Kartik Purnima fair at Hindu pilgrimage Ram Tirath Mandir in Amritsar.