Avani Avittam or Upakramam is celebrated in South India on the full moon day of Shravan (August), which is also the day of the Rakhi Purnima. It is a ritual that is followed by the Brahmins in the southern states of Tamil Nadu, Kerala, Orissa and parts of Maharashtra. The fact that so many different festivals are held on the same day, and yet they seek to dispel the same message truly portrays how India is united even in her diversity.
This is above all a day of retrospection for the Brahmins and a day when they can reaffirm their vows of penitence of all sins committed over the past year. This is also known as Mahasankalp (great aim). This they seek to do by taking a dip in the holy river, a sight which commands immense respect all over the rolling plains of India.
The Brahmins also change their sacred thread on this day every year. Is Brahmin wears a sacred thread since the age of ten which holds great religious significance in his life and the changing of this thread symbolizes the shedding of all sins and making a new beginning. They renew pledges to keep their Vedic duties towards society and humanity at large. The festival is celebrated as Avani Avittam.
Also called the Upakramam, the beginning, the day recalls the reincarnation of the Lord Vishnu, the preserver in the Hindu trinity of Gods, as Hayagriva, the god of knowledge. The Lord had restored the Vedas to Brahma on this day, hence the festival signifies the beginning of the reading of the Yajur Veda for the next six months.
In Southern India the festival celebrates knowledge and the pursuit of it. Traditionally, Brahmins were known as men of knowledge and they have sought to study the Vedas and derive its meanings over centuries. This continues till day as each Brahmin sets out to achieve the goal of transcendence, oneness with the creator Brahma. This day is celebrated as Nariyal Purnima or Rakhi Purnima in the west and Kajri Purnima in the North.