Upakarma

Upākarma "Beginning" (Sanskrit: उपाकर्म), also called Āvaṇi Aviṭṭam (Tamil: ஆவணி அவிட்டம்) and Janivārada Huṇṇime (Kannada: ಜನಿವಾರದ ಹುಣ್ಣಿಮೆ),Gamha Purnima (Odia: ଗହ୍ମା ପୂର୍ଣିମା), is a Vedic ritual practiced by Hindus of the Brahmin caste. This ritual is also practiced by the Kshatriya and Vaishya community, who are dvijas and therefore have the rights to do Sandhyavandanam, the daily ablution ritual.

Upākarma is conducted once a year during the shravana or Dhaniṣṭhā nakṣatra of the Hindu calendrical month Śrāvana, when Brahmins ritually change their upanayana thread accompanied by relevant śrauta rituals, making śrāddha offerings to the rishis, whom Hindus believe composed the Vedic hymns. The day, also called Śrāvana Pūrnima "Full Moon of Śrāvana" in other parts of India, usually occurs the day after the Śravana nákṣatra, which also marks the Onam festival of Kerala.

On the following day, usually coinciding with the Raksha Bandhan festival in Northern and Central India, the Gayatri Mantra is recited 1008 times.

...
Wikipedia