New moon in Tamil month Aadi — observed for ancestral rites and holy river baths, especially at the seashore.

Aadi Amavasai is the new moon day of the Tamil month of Aadi, and among the most important days of the Tamil ritual year for ancestral worship. Families gather at the sea, at river confluences and at temple tanks — Rameswaram, Thiruvanmiyur, Agni Theertham and the Kaveri ghats draw very large crowds — to perform tarpanam for their departed. The observance is not mourning but obligation: the Tamil tradition holds that the debt to one ancestors is discharged through water offered on this day. Aadi itself is regarded as an inauspicious month for weddings and new ventures precisely because it is given over to the divine feminine and to the ancestors. Many also visit Amman temples on this day.

The person performing the rites fasts until the tarpanam and the feeding are done, then takes a single satvik meal on a banana leaf.