This is celebrated on the Amavasya day in the month of Bhadrapada.
When the sun is in the zodiacal sign of Kanya or virgo and in conjunction
with the moon. It is a very auspicious day for offering oblations
to the pitris that is names of the departed ancestors. The whole fortnight
called pitri pakshas i.e. the fortnight preceding Amavasya is sacred
for propitiating departed souls. People go to sacred rivers
like Ganga in North India, Godavari and Krishna in Andhra and Kaveri
in South India to offer oblations and pindas to their ancestors.
All Hindus take it to be an auspicious day, the twice born that
is dwijas and particularly Brahmins perform the rituals on an elaborate
scale according to the rules laid down in religious manuals.
The lower castes and particularly the poor people remain content with
the offer of a day's ration called Sahityam or Swayampakam (food cooked
one self) to their family priest in the name of their departed ancestors.
The eatables and special dishes are prepared according to the
means of the family. Non vegetarians drink liquor and eat meat
for the satisfaction of the departed ancestor.
