Offering oblations to Ancestors

The sacred days for doing this, this year, are, it seems, 15 September
through 29 September.

Spiritual Calender:
http://dlshq.org/religions/calendar.htm

From:
http://dlshq.org/religions/mahalaya.htm

Mahalaya Amavasya

By
Sri Swami Sivananda

The dark fortnight of Aswayuja (September-October) is known as the
Mahalaya Paksha or the fortnight specially sacred for offering
oblations to the departed ancestors. The last day of this period, the
new moon day, is considered as the most important day in the year for
performing obsequies and rites.

The renowned hero of the Mahabharata, Karna, when he left the mortal
coil, ascended to the higher worlds and the great charity he had done
here was returned to him hundredfold. But, it was all gold and silver;
there was no food, as he had not done any food-charity! He prayed to
the god of death. So, he was sent back to earth for fourteen days, to
make up for this deficiency.

For fourteen days, he fed Brahmins and the poor, and offered oblations
of water. On his return to the higher regions, he had food in plenty.
It is these fourteen days that are commemorated in the Mahalaya
Paksha. Due to the grace of the god of death, it has been ordained
that offerings made during this period benefit all the departed souls,
whether they are connected to you or not.

Charity in the form of food is important during this observance. Life
depends upon food. You cannot preach religion to empty stomachs. This
human body is the most important vehicle for realising God. How
precious must food be which keeps the body fit for Yoga! The gift of
food is the greatest gift. Therefore, give food in plenty, not only
during the Mahalaya fortnight but all through the year.

Also, from:
http://www.dlshq.org/download/hinduismbk.htm#_VPID_51

Sraaddha And Tarpana

Sraaddha is the name of the ceremonies performed by relatives to help
the Jiva who has cast off his physical body in death. A Jiva who has
cast off his physical sheath is called a Preta. The part of the
Sraaddha performed to help him at this stage is called the Preta
Kriya.

How Sraaddha And Tarpana Benefit The Departed Souls

Gifts to deserving Brahmanas for the benefit of the Pitris, in the
proper time and place and with faith, are known as Sraaddha. Sraaddha
gives satisfaction to the Pitris. By the offering of the sixteen
Sraaddhas, the son helps his father to dwell in joy with the Pitris.
The son should perform the Sapindikarana rites for his father.
Performance of Sraaddha and Tarpana relieves the hunger and thirst of
the departed soul during its journey to the Pitri Loka.

Those who go to hell are extremely oppressed by hunger and thirst.
Performance of Sraaddha and offerings of rice and oblations to them,
relieve their sufferings. Hence, performance of Sraaddha is
indispensable. Those who dwell in heaven also get satisfaction,
strength and nourishment.

The Advantages Of Cremation

Cremation is the best way of destroying a dead body. This is highly
beneficial for the departed soul. If the body is not burnt; the Jiva
is linked to the earth. The soul hovers round or hangs about the dead
body on account of Moha or attachment to the physical body. Its
journey to the celestial regions is interfered with. The vibrations
set up by the recitation of Mantras and the offerings and oblations of
water, bring solace and comfort to the departed soul. The
Sapindikarana ceremony helps the Jiva to pass from the Preta Loka to
the Pitri Loka. He is then enrolled among the Pitris or the ancestors.
The son walks three times round the dead body of his father before
fire is set to the pyre and sprinkles water once, reciting the Mantra:
“Go away. Withdraw and depart from here.” The bones are collected on
the next day and thrown into a river. Those who can afford take them
to Benares or Haridwar and throw them into the Ganga. It is believed
that the soul whose mortal remains are consigned to the sacred Ganga
attains to the higher regions of spiritual light and splendour and, in
the end, salvation.

The Two Classes Of Pitris

Immediately after death, the Jiva obtains the Ativahika body which is
made up of fire, air and ether. Later on, it may have a Yatana Deha
for suffering the tortures of hell if it had done great sins on the
earth-plane, or a celestial body for enjoying the pleasures of heaven
if it had done virtuous actions while living in the world. In the
Yatana Deha, the air-element preponderates; while, in the celestial
body, the element of fire is dominant. It takes one year for the Jiva
to reach the Pitri Loka.

There are two classes of Pitris, viz., the celestial Pitris who are
the lords of the Pitri Loka, and the human Pitris who go there after
death. Brahma is the paternal grandfather of all. Kasyapa and the
other Prajapatis are also Pitris, as they are the original
progenitors. Pitri Loka or the Abode of the Pitris is also called by
the name Bhuvar Loka.

The word Pitris primarily means the immediate ancestors, viz., father,
mother, etc. Sraaddha proper is performed for three generations of
Pitris, or to all Pitris. Three cakes are offered to the father, the
grandfather and the great grandfather. Two Brahmins are fed first.
Seven generations can mutually influence one another by the giving and
receiving of food.
Pitripaksha And Mahalaya Amavasya

The dark fortnight of the month of Asvayuja is known as the
Pitripaksha or the fortnight of the month specially sanctified for
offering oblations to the departed ancestors. And the last day, the
day of the new moon, is considered as the most important day in the
year for performing obsequies and like rites.

Now, ordinarily, the orthodox Hindus offer oblation of water—Tarpana-
Arghya—to the departed every new-moon day. The prescribed rites are
also performed every year on the anniversary of the day of death. This
is the Sraaddha ceremony. What, then, is the special import of these
observances particularly during the Asvayuja Krishna Paksha? The
reason is that such ceremonies done during this fortnight have a very
special effect. The offerings reach the Pitris immediately and
directly, due to a boon from Lord Yama. The occasion for the boon
arose as follows:

Origin Of The Pitripaksha

A Story from the Mahabharata

The renowned hero of the Mahabharata, Danavira Karna, when he left the
mortal coil, ascended to the higher worlds and reached the region of
the heroes. There, the fruit of his extraordinary charity while upon
earth came to him multiplied thousandfold, but it came to him in the
form of immense piles of gold and silver. Karna had done limitless
charity of wealth, but had neglected to do Anna-Dana. Thus he found
himself in the midst of wealth and plenty, but with no food to appease
him. He prayed to Lord Yama. The Great Ruler responded to Karna’s
prayer and granted him a respite for fourteen days to return to the
earth-plane once again and make up for his former neglect. Karna came
down from the Mrityu Loka, and for fourteen days, he fed the Brahmins
and the poor, and made offerings of water, etc. He performed the
prescribed rites also on the last day. On his return once again to the
higher world, the effect of Karna’s observances during this fortnight
removed all his wants there. The time of this occurrence was the dark
fortnight of Asvayuja.

Due to the grace of Lord Yama, it came to be so ordained that such
rites done at this particular period acquired the following unique
merits. Offerings made at this time reached all departed souls,
whether they were kins directly in the line of the offerer or not.
Even those who died without progeny received these oblations given on
this Pitripaksha Amavasya day. All those who had failed to do deeds of
charity and Anna-Dana and were thus denied these comforts in the Pitri
Loka, benefited by these ceremonies. Those deceased whose date of
death is not known and whose annual Sraaddha cannot be done, they also
get these oblations of Pitripaksha. Souls whose life was cut off by
violent, accidental or unnatural death and to whom, therefore,
offerings cannot reach in the ordinary course, to them, too, the
Pitripaksha offerings reach directly. All these the boon of Lord Yama
made possible from the time the great Karna performed the Asvayuja-
Paksha rites. The Hindus now observe this Paksha with great faith,
with strict regulation, taking bath thrice, with partial fasting, etc.
On the newmoon day, Sarvapitri Amavasya, the full rites are done and
plenty of charity given.

Propitiation Of Departed Spirits

The day of Mahalaya Amavasya is a day of great significance and
importance to all Hindus. It is the annual festival for propitiating
the spirits of our ancestors, with devout prayers for peace. The Hindu
Itihasas say, that on the Mahalaya Amavasya, there is a conjunction of
the sun and the moon and that the sun enters the sign Virgo (Kanya).
On this day, the departed manes, i.e., our ancestors, leave their
abode in the world of Yama and come down to the world of mortals and
occupy the houses of their descendants.

The fortnight preceding the new moon is specially consecrated for the
propitiation of such departed spirits. The ceremonies performed in
honour of the manes or ancestors during each day of this fortnight are
considered to be equal to those performed at Gaya. The principle in
all such rites is the worship of the departed souls and the
satisfaction of their wishes so that they might be in peace during the
rest of the year.