Aadi Amavasai – the no moon day in the Tamil month Adi or Aadi – is dedicated to ancestors. Amavasai is also an important day for Lord Muruga devotees. The important ritual involves taking bath in the holy rivers. Special poojas and abhishekams are conducted in all the Hindu temples on the occasion. In 2011, the date of Aadi Amavasai is July 30.

Lord Muruga devotees believe that all sins will be cleansed by bathing in the Shanmuga River in Palani on the Aadi Amavasai day. Many devotees also tonsure (shaving the head) on the day.

The main rites and rituals on the day are dedicated to forefathers and many people observe ‘upvaas’ or fast. Thousands of people take a holy dip in the various rivers, seas and ponds. Agni Theertham in Rameswaram, Thriveni Sangamam in Kannyakumari and various holy ghats on the Cauvery River banks are favored by many devotees for the holy dip.