Upakarma means beginning or Arambham and it refers to the ritualistic beginning of learning Veda. Apart from learning Vedas on Upakarma day, Brahmins ritually change their Upanayana thread along with Shrauta rituals. Those who follow Yajurveda observe the Upakarma on the full moon day during Shravan month i.e. on Shravana Purnima day. Those who follow Rigveda observe the Upakarma on Shravana Nakshatra day in the month of Shravana.