Overview
Kartik Purnima (Sanskrit: कार्त्तिकपूर्णिमा, Kārttikapūrṇimā), also spelt Kartika Pournami, is a cultural and religious festival observed in Hindu, Sikh, and Jain traditions. It is marked on purnima, the full moon day that falls on the fifteenth of the lunar month of Kartika.
In the Gregorian calendar, the festival usually falls in November or December, and follows Diwali by about a fortnight. It is also known as Tripurari Purnima or Deva-Deepavali, often described as the gods' festival of lights.
Karthika Deepam, a related festival celebrated in South India and Sri Lanka, is observed on a different date and is distinct from Kartik Purnima, though both fall within the lunar month of Kartika and share themes associated with light.
References
Adapted from the English Wikipedia article on Kartika Purnima.