Jandhaya Purnima or Janai Poornima is the ritual observed on Shravana Pournami in Andhra Pradesh. In 2012, Jandhyala Purnima date is August 2. Jandhayla Purnima is called as Janai Purnima in Karnataka.
Jandhyam means the Yagnopavitham or the Sacred Thread. Changing of Sacred Thread is performed on Jandhyala Purnima day. Jeerna Yagnopavitham (old Sacred Thread) is removed and new sacred thread is worn on this day. Mainly Dwijulu or the Brahimins in Andhra Pradesh perform the act of Jandhya dharana or Yagnopavitha dharana on Shravan Purnima.
The performers of Jandhya dharana perform ritual bath in rivers or lakes or even in house and sanctify the puja room. Maha Sankalpam is recited during the Janeyu dharana. Jeerna Yagnopavitham is removed while reciting Jeerna yagnopaveetha mantra. New Janai is worn after reading Gayatri Mantram.
After the first year of Upanayanam, Upaakarma is observed on Shravan Pournami. Jandhyala Purnima is also referred as Upaakarma in some other places of South India. In Tamil Nadu Janai Purnima is observed as Avani Avittam.
The Brahmins who missed the opportunity to change the Sacred Thread on Shravana Pournami, will perform the ritual on Bhadrapada Purnima.