It's believed that this presents a chance for those spirits to visit the living, move on to their next life or reincarnate to a better realm.
Thus this period is known as the month of the Hungry Ghosts.
Vietnamese people consider this month to be unlucky. As a result, they usually adopt a vegan diet, perform good deeds, and avoid a number of actions that are deemed as taboo. In accordance with the festival, it's recommended you:
- Avoid going out at night. If you do go out at night in a group, don’t call each other, or else the spirits will learn your names
- Don’t remove your leg hair, spirits tend to avoid people with more leg hair
- Don’t swim in the water as the spirits might grab your legs
- Don’t hang clothes out at night as the spirits might be attracted to it
- Don’t pick up money from the street, as it might be offered to the spirits
- Don’t turn your head If someone follows or calls your name from behind at night
- Don’t stab your chopsticks into the rice bowl as it represents joss sticks and makes it look like you’re offering food to the spirits
- And so on, depending on the region...

People throw 'hell money' for burning as part of the festival. Source: AP
Food offerings include congee, rice, salt and water, along with a number of other dishes.
Diluted congee is preferred as it is believed the hungry ghosts have a narrow esophagus and cannot digest common food.
After the offering, people will scatter rice and salt on the street, and burn "hell banknotes" and other forms of joss paper.
In some regions, children are allowed to grab the food for themselves.

People watch as a hungry ghost effigy is burned. Source: Sarah Enticknap
The Ullambana Festival
The Hungry Ghosts Festival coincides with the Buddhist festival of Ullambana, or “Vu Lan” in Vietnamese.
According to Buddhist sutra, when Maudgalyayana, one of the ten great disciples of the Buddha, discovered that his deceased mother was suffering in the hungry ghost realm, he asked the Buddha for guidance.
The Buddha then told him to offer food to the monastic community in the 15th day of the seventh lunar month, and asked them to transfer the merits to his deceased mother.
Thus the Ullambana Festival was established.
In Vietnam, Ullambana is also considered Mother’s Day, when people honour their parents and ancestors.

An effigy of a hungry ghost before it is burned. Source: Sarah Enticknap
People with living mothers, and sometimes fathers, would bear a red rose, while those without bear a white rose.
Therefore, this festival is also an opportunity for people to respect and pay tribute to their parents and ancestors.
Hungry Ghosts premieres on SBS at 9:30pm Monday 24 August and airs over four consecutive nights till Thursday 27 August. Episodes with Vietnamese subtitles will be available at SBS On Demand each day at the same time as broadcast.