Annual Shraddha — also called Thevasam or Aandu Thithi — is the yearly rite performed in memory of a departed parent or ancestor. It is observed not on the English date of death, but on the lunar day (Tithi) that was running at the exact moment of passing. Through tarpanam, pindam and anna-danam (offering of food), it seeks peace for the departed soul and the ancestors' continuing blessings for the family. It is usually carried out by the eldest son or a male descendant, following family custom, often with a priest.

Mahalaya Shraddha is performed during Pitru Paksha — a sacred fortnight (the waning-moon half of Purattasi / Bhadrapada month, usually September–October). During these days the ancestors are believed to descend to bless their descendants, so shraddha offered now is held to be especially meritorious. Ideally it is done on the Tithi matching the ancestor's own death Tithi within this fortnight. The final day, Sarvapitri (Mahalaya) Amavasya, is reserved for honouring all ancestors together — and is the day to perform the rite if the exact Tithi was missed or is unknown.