Krishna Janmashtami, also known simply as Janmashtami or Gokulashtami, is an annual Hindu festival that celebrates the birth of Krishna, the eighth avatar of Vishnu. It is observed according to the Hindu lunisolar calendar, on the eighth day (Ashtami) of the Krishna Paksha (dark fortnight) in Shraavana or Bhadrapada (depending on whether the calendar chooses the new moon or full moon day as the last day of the month), which overlaps with August or September of the Gregorian calendar.
It is an important festival, particularly in the Vaishnavism tradition of Hinduism. Dance-drama enactments of the life of Krishna according to the Bhagavata Purana (such as Rasa Lila or Krishna Lila), devotional singing through the midnight when Krishna was born, fasting (upavasa), a night vigil (Ratri Jagaran), and a festival (Mahotsav) on the following day are a part of the Janmashtami celebrations. It is celebrated particularly in Mathura and Vrindavan, along with major Vaishnava and non-sectarian communities found in Manipur, Assam, Bihar, West Bengal, Odisha, Madhya Pradesh, Rajasthan, Gujarat, Maharashtra, Karnataka, Kerala, Andra Pradesh, Tamil Nadu and all the other states of India.
Krishna Janmashtami is followed by the festival Nandotsav, which celebrates the occasion when Nanda Baba distributed gifts to the community in honor of the birth
Hindus celebrate Janmashtami by fasting, singing, praying together, preparing and sharing special food, night vigils, and visiting Krishna or Vishnu temples. Major Krishna temples organize recitation of ‘'Bhagavata Purana and Bhagavad Gita. Many communities organize dance-drama events called Rasa Lila or Krishna Lila. The tradition of Rasa Lila is particularly popular in the Mathura region, in northeastern states of India such as Manipur and Assam, and in parts of Rajasthan and Gujarat. It is acted out by numerous teams of amateur artists, cheered on by their local communities, and these drama-dance plays begin a few days before each Janmashtami.