Pitri paksha depicts the fortnight of the ancestors. It is a 16 lunar day period when Hindus pay homage to their ancestors, significantly through food offerings. The period can also be called Pitri Pakshya, Pitri Pokkho, Sorha Shraddha, Kanagat,Jitiya, Mahalaya Paksha and Apara Paksha.
It falls in the Hindu lunar month of Bhadrapada, beginning with the full moon day that occurs right away after the Ganesh festival and terminating with the new moon day known as Sarvapitri amavasya or Mahalaya amavasya.
Mahalaya marks the formal beginning of the Durga Puja festival. This period corresponds to the dark fortnight of the month Ashwin instead of Bhadrapada in North India and Nepal.
The souls of three preceding generations of one's ancestor reside in pitriloka, a realm between heaven and earth as stated by Hindu mythology. Yama, the god of death, is governor of this realm. He takes the soul of a dying person from earth to pitrilok. The first generation only shifts to heaven and unites with god when a person of the next generation passes away.
As claimed by Hindu epics, the sun enters the zodiac sign of virgo, coinciding with this moment it is believed that spirits leave pitri loka and reside in their progeny's homes for a month unless the sun enters the next zodiac sign Scorpio.
During the dark fortnight, Hindus are expected to make peace with their ancestors in the first half.Roots of its origin are grounded in the epic Mahabharata war, when the legendary donor Karna demised, his soul transcended to heaven, where he was offered gold and jewels as food. When he asked Indra,the lord of heaven,the reason behind serving gold as food.
Indra told Karna that he had donated gold all his life however he never donated food to his ancestors in Shraddha later realizing his blunder as he was unaware of his ancestors he was permitted to return to earth for 16 days so that he could perform Shraddha as well donate food and water in the memory of his ancestors.
According to Hindu mythology, every individual who wants to perform this Pitri Tarpan ,they should do it on the same day their ancestor died which will fall within any one of these fifteen days.
There are exceptions to the lunar day rule; special days are allotted for people who died in a particular manner or had a certain status in life.The fifteen days of Malaya Paksha consists of 15 Tithi. They include Pratipat, Dvitiya, Tritiya, Chaturthi, Panchami, Trayodasi, Chaturdashmi, Amavasya. The performance of Shraddhas by a son during Pitri Paksha is regarded as a compulsory rite by Hindus, to ensure that the soul of the ancestor goes to heaven.
The scripture Garuda Purana says,'' there is no salvation for a man without a son''.The scripture Markandeya Purana says that if the ancestors are content with the shraddhas, they will bestow health, wealth, knowledge and longevity and ultimately heaven and salvation upon the performer. The ceremony is central to the concept of lineages.
Sarvapitri amavasya is deliberated for all the ancestors, regardless of the lunar day they dies.It is the most important day of the pitri paksha. Those who have forgotten to perform shraddha can perform on this day.Bengali people traditionally wake up early in the morning on Mahalaya to recite hymns from the Devi Mahatmyam scripture. Matamaha marks the first day of the month of Ashvin and the beginning of the bright fortnight. It is assigned for the grandson of the deceased maternal grandfather.The shraddha is performed only at noon, usually on the bank of a river or lake at one's house.
It is essential that Shraddha ought to be performed by the son, usually the eldest. The one who performs should take a purifying bath beforehand and should wear dhoti. He wears a ring of Kush. It is usually performed bare-chested as the position of the sacred thread worn by him needs to be changed multiple times during the ceremony. It involves pinda daan which is an offering to the ancestors of pindas. It is cooked rice and barley flour balls mixed with ghee and black sesame seeds, accompanying the release of water from the hand. The offering is considered to be accepted if a crow arrives and devours the food; the bird is believed to be a messenger from Yama. A cow and a dog are also fed. Once the ancestors(crow) and Brahmins have eaten, family members can proceed with their prasad.
Ancestors are taken as the centre of God and the ancestral homage is taken as the centre of eternal rites. It elucidates the height and importance of Vedic Sanatan rites.