Kartik poornima is also the birthday of Matsya, god Vishnu’s fish-incarnation (Avatar). It is also the birthday of Vrinda, the personification of the Tulsi plant and of Kartikeya, the god of war and son of Shiva. This day also is considered special for Radha, the lover of Krishna – Vishnu’s incarnation. It is believed that Krishna and Radha danced rasa and Krishna worshipped Radha on this day. This day is also dedicated to the pitrs, dead ancestors.
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.
The festival has even more significance when the day falls in the nakshatra (lunar mansion) Krittika and is then called Maha Kartik. The nakshatra is Bharani, the results are stated to be special. If it is Rohini nakshatra, then the fruitful results are even much more. Any philanthropic act on this day is supposed to bring benefits and blessings equal to the performing of ten yajnas (sacrifices).
Kartik Poornima is closely associated with Prabodhini Ekadashi which marks the end of Chaturmas, a four-month period when Vishnu is believed to sleep. Prabodhini Ekadashi signifies the awakening of the god. Chaturmas penance ends on this day. Many fairs that begin on Prabodhini Ekadashi end on Kartik Poornima, Kartik Poornima usually being the most important day of the fair. Fairs that conclude on this day include Prabodhini Ekadashi celebrations at Pandharpur and Pushkar Fair. Kartik Poornima is also the last day to perform Tulsi Vivah ceremony that can be performed from Prabodhini Ekadashi.
Also, it is believed that Vishnu, on this day, returns to his abode after completing his stay in Bali. Hence, the day is known as Deva-Diwali.
In Pushkar, Rajasthan, the Pushkar Fair or Pushkar mela commences on Prabodhini Ekadashi and continues till Kartik Poornima, the latter being the most important. This fair is held in honour of god Brahma, whose temple stands at Pushkar. A ritual bath on Kartik Poornima in the Pushkar Lake is considered to lead one to salvation. It is believed circling the three Pushkars on Kartik Poornima is highly meritorious. Sadhus gather here and stay from ekadashi to full moon day in caves. About 200,000 people and 25,000 camels assemble in Pushkar for the fair. Pushkar fair is Asia’s largest camel fair.
A ritual bath at a tirtha (a sacred water body like a lake or river) at a pilgrimage centre is prescribed on Kartik Poornima. This holy bath is known as “Kartik snana”. An holy bath at Pushkar or in the Ganges river, especially at Varanasi is deemed as most auspicious. Kartik Poornima is the most popular day for bathing in the Ganges at Varanasi. The devotees also take a bath in the evening during moonrise and offer worship by way of six prayers such as Shiva sambuti, Satait and so forth.
Annakuta, an offering of food to the deities, is held in temples. People who have taken vows on Ashwin full moon day, end them on Kartik Poornima. God Vishnu is also worshipped on this day. Any form of violence (himsa) is prohibited on this day. This includes shaving, hair-cutting, cutting of trees, plucking of fruits and flowers, cutting of crops and even, sexual union. Charity especially donation of cows, feeding of Brahmins, fasting are religious activities prescribed for Kartik Poornima. Giving gift of gold is said to fulfill all desires of people.
Tripuri Poornima is only next to Mahashivratri, amongst festivals dedicated to Shiva worship. To commemorate the killing of Tripurasura, images of Shiva are carried in procession. Temple complexes in southern India are lit up throughout the night. Deepmalas or towers of lights are illuminated in temples. People place 360 or 720 wicks in temples, to secure escape reaching hell after death. The 720 wicks symbolizes the 360 days and nights of the Hindu calendar. In Varanasi, the ghats come alive with thousands of diyas (brightly lit earthen lamps). People gift lamps to priests. The lamps are kept throughout the night in houses and Shiva temples. This day is also known as “Kartik Diparatna” – the jewel of lamps in Kartik. Lights are also floated in miniature boats in rivers. Lights are placed under Tulsi, Sacred fig and Amla trees. The lights in the water and under trees are believed to help fishes, insects and birds who saw the light to attain salvation.[