Raksha Bandhan (Shravan Purnima) is celebrated as Avani Avittam in Kerala, Andhra Pradesh, Tamilnadu and parts of Orissa and Maharashtra. Avani Avittam is considered an important day for the Brahmins in southern states of India. The day is called Upakarmam (meaning the beginning) by the Brahmins. The Brahmins change their Holy threads (Yajnopavita or Janeyu) and read the Yajurveda on this day.
People take Mahasankalpam or a vow for atonement of all their sins in the past. The Brahmins take a holy dip and wear a new holy thread called Yajnopavita or Janeyu. When the thread (Yajnopavita) is worn, another mantra is recited which means -"I am putting on the sacred thread which is highly pure, inseparable from God, is capable of prolonging life and is most important in the accomplishment of a Brahmana.