Upakarma festival is solely for the men. The others also join in by preparing delicious food as naivedhyam / blessed food and eating together. This festivals falls on Shravana Nakshatra (a star) on the full moon day of Hindu month Shravana. August – September in Gregorian calendar. This festival is celebrated on different days by followers of Rigveda and Yajurveda based on the occuring of Shravana nakshathra according to their predictions. This year (2016) Yajur Upakarma is on 18th August and Rig Upakarma is on 17th August.
On this day, Brahmin, Kshatriya and Vaishya men change the old yajnopavita (sacred thread worn during the upanayana/munji/sacred thread ceremony). They worship the saptha (seven) rishis (sages) and pray for prosperity. They chant the Gayathri Mantra before and after wearing the sacred thread.
Cooked vermicelli and Kayi Bella / coconut mixed with jaggery is offered as naivedhyam.