Udaya Tithi Chaturdashi of Magha Krishna Paksha will remain till 02:19 pm on 31st January. After that new moon will take place. Amavasya Tithi will start from 2:20 pm on January 31 and will last till 11.16 am on February 1. According to Acharya Indu Prakash, when Amavasya is celebrated for two days then the first day marks Shraddha Amavasya and on the second-day people do charity and take a dip in holy water. Therefore, on January 31, the Shraddha of Magh month is the new moon of Tarpan (It refers to the act of offering as well as the substance used in the offering). On this day Shraddha and Tarpan of ancestors should be done.
According to the Hindu calendar, it is considered as one of the most auspicious days and is observed every year on the new moon day. This is also called Magha or Mauni Amavasya.
To get rid of Pitra Dosh and to get the blessings of one's ancestors, making milk and rice kheer, burning cow dung cakes or sticks and offering kheer on it remembering the ancestors is considered auspicious. After offering the bhog, take some water and leave it on the right-hand side, that is, on the left side of the bhog for added benefits.
If you can not make milk-rice kheer, then offer whatever pure fresh food is prepared in the house to the ancestors, as well as fill water in a pot with Gangajal, a little milk, rice grains. The ancestors should be offered tarpan by putting sesame seeds and facing the south direction. You will also get benefit from this.