The 15th Day of 7th Moon in Lunar Calendar - Ullambana
Ullambana (Sanskrit), is the festival of “all souls”, the prototyoe of All Soul’s Day in Christian lands. In actual mean, is interpreted as “to hang upside down”. This is to describe hungry spirits – their esophagus is as narrow as a needle, their belly is as big as a drum. They cannot eat nor drink and are always hungry. Even though there is food, it will turn into charcoal as soon as it is swallowed. The pain is similar to being hung upside down. "Bana" is a vessel filled with offerings of food and it has the meaning of salvage. In other words, Ullambana means to save from being hung upside down and to relieve of pain.
The Buddhist origins of the festival can be traced back to a story that originally came from India, but later took on culturally Chinese overtones. In the Ullambana Sutra, there is a well descriptive account of a well-to-do merchant who eventually gives up his trade to become a Buddhist monk. He became one of the Buddha's chief disciples. His name was Mahāmaudgalyāyana. (Ch. 目連, Mulian, Pāli Mahāmoggallāna)
After he attained the title of arhat, he thinks of his father and mother, and wonders what happens to them. He travelled over the known Buddhist universe, and found his father in heaven.
However, his mother was reborn in a lower realm, known as the Realm of Hungry Ghosts. His mother took on the form of a hungry ghost---it could not eat because its throat was very thin and no food could pass through, yet it was always hungry because it had a fat belly. His mother was greedy with the money he left her. He had instructed her to kindly host any Buddhist monks that ever came her way, but instead she withheld her kindness and her money. It was for this reason she was reborn in the realm of hungry ghosts.
Mahāmaudgalyāyana eventually saves her from this plight by battling various demons and entreating the help of the Buddha. The compromise that was made was one that owes to the relevance of the Ghost Festival and ancestor worship.
The Buddha established a day after the traditional summer retreat (the fifteenth day of the seventh month in the lunar calendar--usually mid-to-late August) as a day of prayer and offering in which monks can pray and make sacrifices on behalf of dead ancestors or hungry ghosts. The family members of the deceased essentially pay for this service, and thus their patronage is a form of charity. The deceased ancestors are pacified and hungry ghosts can eat (the sacrificial foods).
The story ends with this festival and the rescue of his mother from hell. She ended up being reborn as a dog, but as a pet in a well-off household.
Another than commemorating the departed ones, in this month, monks and nuns will confess for their sins. according to Buddhist regulations, each summer during the 90 days from the 15th day of the 4th moon to the 15th day of the 7th moon, monks and nuns will not go out to convert. They will assemble together. During the summer retreat, they will follow the rules strictly, purify their acts, and concentrate on the right path. The last day is to dismiss the summer retreat.
On the last day, the monks and nuns will confess their sins. First, they will evaluate whether they gave committed any physical, verbal or mental sins. secondly, they will invite other monks and nuns to comment on their opinion, what they hear and what they doubt. Monks and nuns will the confess their sins at the assembly, correct their mistakes and restore to purity. After dismissing the summer retreat, monks and nuns might attain four kinds of Hinaya, i.e. early fruit, second fruit, third fruit and fourth fruit.
But why did Buddha want his disciples to hold the summer retreat? Buddhist followers normally practice near the bottom of hills or forests or close to water. During the summer, flooding occurs frequently in India. For all followers' safety, Buddha implemented this regulation which requires monks to assemble together to spend the summer. Besides, Summers in India are humid. It is the season for snakes and insects to grow. The summer retreat will avoid monks from being hurt by these insects and at the same time prevent the monks from hurting these insects, as they will not be going out.
Indeed, it’s also Buddha’s joyous day, here human beings becoming good rather than evil, understanding rather than superstitious, and being true rather than false after self-confession.
From this, as you can see, the way we celebrate this special occasion is slightly different from the Taoism. I’m sure most of the people would mess up this day with Taoism Hungry Ghost Festival since they are falling in the same month. Ullambana festival chiefly reinforces the concept of filial piety. It signifies the importance of performing "good deeds" to accumulates spiritual merit. Most significant is to share the merit with the departed souls, to help them reborn in good realms and end their suffering.
As World-Honoured One told Ksitigarbha Bodhisattva “if in the future, humans or gods who ought to fall into the evil paths as karmic retribution are on the verge of falling into those paths, or are already at the very gates to those paths, or are able to recite the name of the Buddha or Bodhisattva, or a single sentence or verse of a Great Vehicle (Mahayana) Sutra, you should use your spiritual powers to rescue them with expedient means. Display to them a limitless body, smash the hells, and cause them to be born in the heavens and to experience supremely wonderful bliss.”
Chapter XIII :: The Entrustment of Humans and Gods