Sam Shravani is observed on the first day of the Shukla Paksha (waxing phase of moon) of Bhadrapad month. Sam Shravani 2024 date is September 5. On this day, Samvedi Brahmins change their sacred thread known as Janoi or Yajnopavita. This particular name for the ritual is more popular in Gujarat .
It must be noted that there are Brahmins who follow Rig Veda or Yajur Veda or Sama Veda or Atharva Veda. And depending on which Veda they are following, they have a special day for changing the sacred thread. This ritual is more popular with South Indian Brahmins and is known as Upakarma. Those that follow Yajur Veda change the thread on Shravan Purnima day and those that follow Rig Veda on the day before Shravan Purnima.
Those who follow the Sama Veda perform the ritual on the first day of the Shukla Paksha of Bhadrapad Month. This ritual is popular with Brahmin community in South and Western parts of India
The ritual involves chanting of sacred mantras. Saints affiliated to certain sects also change the Janoi on the day.