The day begins before sunrise. Men wake up early and take a holy bath, usually in a river, tank, or at home with rituals involving sesame oil (Neyyedu). This bath is not just for physical cleanliness but is believed to purify the soul.
Exact dates depend on the lunar calendar. Typically, it falls in August. (Please check a Tamil Panchangam for exact year-specific dates). avani avittam tamil
In the Tamil Bhakti tradition, while Alwars and Nayanmars moved away from ritualism, they acknowledged Avani Avittam as a day of Mapu (forgiveness). It is a day to ask for pardon for the sin of cutting trees, stepping on books, or reciting Vedas incorrectly. The day begins before sunrise