Pitru Paksha is a 16- day ritualistic period dedicated to the departed souls in the Hindu customs. Hindus consider Pitru Paksha to be inauspicious due to the death rite performed during the ceremony, known as Shraddha or Tarpana. Pitru Paksha means “fortnight of the ancestors” and follows the fortnight immediately after the Ganesh Chaturthi festival. According to the ancestral customs this Paksha (phase) is primarily meant for paying tributes to dead relatives for pleasing them and asking for forgiveness. The day is meant to free oneself from the curse of the ancestors which is also called Pithru Dosha.
The common belief in the Hindu religion is that the soul wanders in various worlds after a person dies. People perform shradh rituals and repay their debts to the dead ancestors to ensure it finds peace and tranquility and blesses the living.
The legend behind Pitru Paksha is that, when Karna passed away during the war of Kurukshetra and his soul reached heaven, he didn’t get to eat regular food like others. Instead, he was given gold and jewels to eat. His soul got frustrated and he addressed this issue to Lord Indra as to why he is not being served actual food like others. Lord Indra revealed the actual reason that he donated all these things to others throughout his life but never gave the same to his ancestors. After hearing Karna's explanation, Lord Indra allowed him to return to Earth for 16 days so that he could donate food to his ancestors. This 16-day period came to be known as Pitru Paksha.
Aasan Shuddhi, Shareer Shuddhi, Pavtrikaran, Ganga Ahvahan, Shikha Bandhan, Swastivachan, Shanti Paath, Sankalp, Dev Tarpan, Rishi Tarpan, Pitra Tarpan, Pind Daan, Panch grass rituals are some of the pooja rituals associated with Pitru Paksha