Naga Panchami is a day of traditional worship of Nag (or Naja or Naga) or snakes (which are associated with the mythical Nāga beings) observed by Hindus, Jains, and Buddhists throughout India, Nepal, and other countries where Hindu, Jain, and Buddhist adherents live. The worship is offered on the fifth day of bright half of lunar month of Shravana (July/August), according to the Hindu calendar. Some Indian states, such as Karnataka, Rajasthan and Gujarat, celebrate Naga Panchami on the dark half (Krishna Paksha) of the same month. As part of the festivities, a Naga or serpent deity made of silver, stone, wood, or a painting is given a reverential bath with milk and their blessings are sought for the welfare of the family. Live snakes, especially cobras, are also worshipped on this day, especially with offerings of milk and generally with the assistance of a snake charmer.
In the Mahabharata epic, the sage Astika stops King Janamejaya from sacrificing and eventually decimating the serpent race (Sarpa Satra). This sacrifice was performed by Janamejaya to avenge the death of his father Parikshita, who was killed by Takshaka, the king of the snakes. The day that the sacrifice was stopped was on the Shukla Paksha Panchami day in the month of Shravana. During this sacrifice, the Mahabharata as a whole was first narrated by the sage, Vaisampayana. That day has since been observed as Naga Panchami.
Panchami is the fifth day among the fifteen days of the moon's waxing and/or waning. This special day of the serpent worship always falls on the fifth day of the moon's waning in the Lunar Hindu month of Shravana July/August. Hence this is called Naga Panchami (Naga: cobra; or simply, serpent).
There are many legends in Hinduism and folklore narrated to the importance of worship of snakes. According to Hindu Puranas and the Mahabharata, Kashyapa, grandson of the universal creator Lord Brahma, married two daughters of Prajapati Daksha, Kadru and Vinata.