Amāvasyā, the New Moon is considered most auspicious for worshiping ancestors. It is said that our ancestors visit the Earth plane on the night of Amāvasyā. “Feeding” our ancestors on this night makes sure that their needs are taken care of so they can focus on showering their blessings on us.

WHEN
Starts at 6:23 AM Pacific Time Aug 13, Thursday morning
Ends at 7:53 AM Pacific Time Aug 14, Friday morning

There are many ceremonies and offerings one can make to ancestors. Some of them include offering a Janeu (sacred thread) to a pipal tree and worship the pipal tree, chanting mantras while going around it 108 times. But in this day and age it is hard to find a pipal tree, let alone do all the rituals associated with it.

Easiest remedy is chanting the following 2 mantras while keeping our ancestors in mind on this day. Pictures of our ancestors should only be hung or displayed on the South wall of the house. It is good to light an incense in front of their picture.

Pitri (ancestral) mantra for Krishna: worshiping ancestors through Krishna.

ॐ नमो भगवते वासुदेवाय नमः
Om Namo Bhagvate Vāsudevāya Namaha

This mantra is for Krishna. Krishna is considered the supreme among ancestors. In Bhagwat Gita Chapter 10, verse 29 Sri Krishna explains:

अनन्तश्चास्मि नागानां वरुणो यादसामहं
पितृणामर्यमा चास्मि यमः संयमतामहम्।।29।।

Of all the many headed non-poisonous Nāgās (deified serpents) I am the divine serpent Ananta. Of all aquatics, I am Varuna, the lord of all beings who live in water. Among the deified ancestors I am Aryamā. Of all administrators of justice, I am Yamarāj, the judge of all beings at the time of death.

Simple Pitri (ancestral) Mantra: In this mantra we are directly invoking them and offering our respects.

ॐ पितृभ्यः नमः
Om Pitribhyaha Namaha