After the full moon of Bhadrapada month, Ashwin month will start. 15 days of this month are for ancestors. This year, the full moon of bathing and donation is on 17 September. Mahalaya will also start from this day. This year, Pitru Paksha will also start from Wednesday, 18 September. Pratipada’s Shradh will be done on 18 September itself. Shradh will continue till 2 October, after which Navratri will start. These 15 days are considered for ancestors, in which their Shradh should be done on their death date. On the day of Shradh of your ancestors, their Shradh should be done by offering tarpan to them. In Shradh Karma, grass is taken out during Tarpan. Actually, grass of food is taken out. In this, one part is given to cow, one part to fire, one part to dog, one part to crow.
Pitru Paksha dates: Shradh is performed for 3 generations, see the list of Pitru Paksha dates
Taking out their grass means that through them our shraddha reaches our ancestors. It is also said that in this the crow is considered to be the form of ancestors. It is believed that to receive the shraddha, our ancestors come to earth on the fixed date in the form of crows and receive the shraddha. If they do not get the shraddha, they become angry. For this reason, the first part of the shraddha is taken out for the crow. After this, grass is taken out for the cow, taking out grass for the cow removes the planetary obstacles. Apart from this, taking out grass for the dog removes all negative powers. At the same time, fire is considered the most sacred, so a grass is also taken out for the fire. In Pitru Paksha, the tarpan for the ancestors is completed only when all these grass are taken out and given. After this, water is offered to the Sun. Only after this, food is served to the Brahmin.