THIS is the night when the cold wind howls, the spirits wander and people go home to their families before dark to gather around a table for a fine dinner.

This is the Winter Dolstice, or dongzhi, the 24 hours when the cold yin energy in the universe is the most powerful, but at the peak of the solstice the cosmic energy shifts, warm yang energy begins to rise and yin declines.

And to make this night even more cosmically significant, this is the first time in 456 years that the solstice (the day with the shortest daylight and longest night) overlaps with a total lunar eclipse (though not significantly visible in China).

Chinese people consider the Winter Solstice the true beginning of the new year, instead of the Chinese Lunar New Year or Spring Festival, and it's said that after the solstice we get a year older.

The solstice festival originated more than 2,500 years ago during the Spring and Autumn Period (770-476 BC). Ancient Chinese marked the day by observing the sunrises and sunsets with tugui, a wooden stick inserted in the earth to record the movement of the shadow cast by the movement of the sun.

Dongzhi was the first solar term Chinese have observed - the year is divided into 24 solar terms.

At this time of changes, the idea of family is very important, as well as respect for ancestors, and sometimes offerings to please their spirits.

The traditional food eaten around tables this night is tangyuan, glutinous rice balls symbolizing reunion. The rice balls are generally eaten in southern China, with a soup, as well as steamed red beans for good luck.

There's a legend that the God of Floods had an evil son who died on the Winter Solstice Day and became a ghost that injured people. But the wicked spirit was afraid of only one thing, red beans. And so there arose a tradition of eating red beans to dispel the ghost and ward off harm.

In northern China, the traditional Winter Solstice food is jaozi, or dumplings. Legend has it that dumplings are eaten to honor the great traditional Chinese medicine master Zhang Zhongjing (150-219 AD) of the Eastern Han Dynasty (25-220 AD).

On one icy winter's solstice Zhang saw that villagers' ears were frozen and frostbitten. The doctor set up a tent on the roadside and cooked ear-shaped dumplings filled with chopped mutton and herbal medicine to dispel the cold. Today the dumplings are stuffed with pork, vegetables and other ingredients.

In Beijing and some northern cities, people eat wonton on the night of the Winter Solstice Day. During the Han Dynasty, the Xiongnu nationality were attacking the border of the Han people and many people died. On the Winter Solstice Day, to curse the invaders and pray for peace, people ate dumplings stuffed with pork meat and called them "Won" and "Tun" after two brutal generals of the Xiongnu.

Energy and spirits

Su Baicheng, a fengshui master and a folk culture expert, says the solstice and the rare total lunar eclipse are both about the Chinese philosophy of yin and yang.

Yang (energy) is embodied in things that are positive, powerful and warm, masculine, such as the sun, fire and the sky. Yin properties are negative, cool, weak and feminine, represented by the moon, water and the soil.

"To be more specific, yang also refers to the living, while yin means the ghost realm, the world of those dead, where their spirits are restless and wandering," the master says.

"The Winter Solstice is the extreme of yin power, but once we pass that day, the yang energy grows gradually. The moon is yin and in an eclipse it's engulfed by the shadow of the earth, which means the return of yang. And this year yang energy will be especially strong."

It is also said that because of powerful yin energy, the door between this world and the netherworld opens for a day and closes at the end of the solstice. During this period of the longest night, ghosts enter the human world and then try to get back home as the door closes.

Lonely souls emerge powerfully on that night, so for many years people used to sweep tombs before the solstice, to please the ghosts of relatives and ancestors. People also might send food to the relatives of those who have passed away, as offerings to spirits. On the solstice night, when families gather, they may burn paper money for the spirits.

It's not a good night to leave home but a good night for spirits to receive offerings.

"It is said that if you go out on this night, you will probably bump into ghosts on the street. Those who are rushing home to get their gifts will let you go, but those lonely souls without a home will run after you," Su says with a half-serious smile.

Weird stories about the night are widespread. One is about shoulder lamps. It is said that metaphysically everyone has two small lighted lamps on their shoulders, which retain the yang energy and protect people from ghosts.

However, when people walk alone at night, especially on the solstice, the lamps are easily extinguished because it's so cold and the yin energy is so strong.

"If you hear somebody calling your name, never turn around," Su says. "The lamps will die in seconds as soon as you turn your head. You are in great danger, vulnerable to the attacks from spirits."

The master says some items carried on the body can act as amulets and help a person repel ghosts; these include articles made of peach wood, gold accessories or a red string tied around the wrist.

But the best advice on this night is to stay home, enjoy your family and eat tangyuan and sweet red beans that send ghosts running.

Less spooky

There are less spooky versions of the Winter Solstice, but they too emphasize respect for and offerings to ancestors' spirits. In every version, spirits return from the other world for the solstice and then return. Some say they are benevolent ghosts of ancestors.

"Let's put aside those spooky stories. The Winter Solstice shows Chinese people's respect and care for life," says Professor Tian Zhaoyuan, director of the college of Anthropology and Folk Culture at East China Normal University.

Traditionally, a meal is prepared for the spirits of the deceased on the night of the solstice because the spirits of the deceased come back home, he said. A round table is laden with good wine and spirit and fine food and set with the best tableware.

"If you look closely, you will find there is always a pair of chopsticks placed to the left side of a bowl - for left-handed ancestors," says Tian. "It's very thoughtful and caring."

The professor says it's remarkable that in a modern city like Shanghai, this tradition of setting a place for the ancestors' spirits is preserved. In many other cities, the solstice passes without such notice.

"This shows the city's great acceptance as well," he says. "Different districts have different customs and they have coexisted in harmony for centuries."

In Yangpu District, wonton is served because these dumplings are shaped like gold ingots, representing wealth and good luck. However in Minhang District, wonton is not allowed on the family altar as it resembles bronze handcuffs, which could catch spirits.

"No matter what version, they all show honor for deceased relatives," Tian says.