Annual renewal of the sacred thread by Yajurveda scholars — performed on the day after Shravan Purnima.

Yajurveda Upakarma, known in Tamil Nadu as Avani Avittam, falls on Shravana Purnima and is the day on which followers of the Yajurveda change the sacred thread and formally resume Vedic study. It is the most widely observed of the three Upakarmas, since the majority of South Indian Brahmin communities follow the Yajurveda. The rite begins with prayaschitta — expiation for lapses in observance during the year — followed by the Kamokarshit japa, the changing of the yajnopavita with its prescribed mantras, and Rishi Tarpanam offered to the seers. The day after is Gayatri Japam, on which the Gayatri mantra is repeated 1008 times. Boys who received the thread during the year perform their first Upakarma on this day.

Participants fast from the morning until the change of thread and the tarpanam are done, then take a satvik meal, traditionally on a banana leaf.