Upakarma (pronounced upaakarma) called Veda Upaakarma or Avani Avittam or Jannivarada Hunnime (Sanskrit: उपाकर्मम; Tamil:ஆவணி அவிட்டம்; Kannada: ಜನ್ನಿವರದ ಹುಣ್ಣಿಮೆ;Oriya:ଶ୍ରାବଣୀ ଉପାକର୍ମ,shravani upaakarma) is one of the ancient Vedic rituals practiced to date. The event is conducted once a year, in the month of Shraavana (mid August - mid September) and all the Brahmins follow it. The main activity performed in an Upakarma is the changing of the Yajnopavita (Yagnopavita) or the Holy Thread, Tarpanam to Rishis and Vedarambha.. The day and its subsequent day are of great significance to Brahmins.

Upakarma, in Sanskrit, means "going near to and implicitly means to the teacher" and historically, the day was considered auspicious for beginning the Vedic studies.

Different sects of people have different dates on which upakarma is performed. Traditional learners of Yajurveda observe the Yajur upakarma in the month of Shraavana (August–September), on the full moon day ; more particularly, Yajur upakarma is held on the full-moon day that comes before the new-moon day of the month of Sravana (Avani). Rig Vedic Upakarma is observed on the day in/on sukla paksha Shravan month which has Shravana nakshatra.Rig Vedic brahmins change the sacred thread on the day,whether purnima is there or not.Shukla Yajurvedic bramhins of North India&Orissa do upaakarma in the preveous day if Purnima spans two days(shukla chaturdashi yukta Purnima). Sama Vedic Upakarma is observed on the day after Shravan Amavasyai,Hastha nakshatra such that they do the Gayatri japam on Ganesh Chaturti.