The Lunar Calendar is based on the movements of the moon, with each month beginning a new moon. The Lunar New Year starts on the first new moon, generally between January 21-February 19.

If the New Year is the time of renewal, Lunar New Year is surely the queen of new years. Renewal is not merely personal but cosmic; parties aren't just thrown for friends and family but for gods and dead ancestors. You can wish Chuc Mung Nam Moi (Greetings of a New Year to You) to the Vietnamese, or Kong Hay Fat Choi (Extend Happiness, Prosperity, and Wealth) to the Chinese. The lunar New Year is the most important holiday in the Asian culture. It is a day of colorful festivities, some as familiar as firecrackers and dragon dances. It is also a day of traditional rituals, rich in symbolism, legends and superstitions dating thousands of years and unknown to non-Asian as well as many Asian American youths.

The Vietnamese New Year, called TET or Tet Nguyen Dan lasts from three days to a week and includes much of the same traditions as the Chinese New Year. Tet Nguyen Dan literally means the first morning of the first day of the new period. It is believed that the course of these few days will determine the path of the coming year. People stop their quarreling, children vow to behave, and families make special efforts to gather together.

Prior to the celebrations homes are cleaned and painted. Cleaning during Tet is avoided so the good luck will not be "swept away". The yellow blossoms of the Hoa Mai decorate the home. New clothes are purchased and old debts are paid. People go to church or the pagoda and offerings are made to the Kitchen God.
Families also paste up strips of red paper "Cau doi"  with sayings of wealth, happiness, prosperity, and longevity. A cau doi, "sentence pair", a literary art form of Chinese origin (parallel sentences), consists of two sentences or lines. Each line corresponds with the other meaning as well as tone pattern and individual word meaning. The cau doi is usually used to convey good wishes on the Tet holidays. It is highly specialized form of poetry.

During this time the Kitchen God departs the home to report on the family. To help protect the home in the absence of the Kitchen God the families erect a Cay Neu, a "New Year Tree". A bamboo pole is planted in front of the home, all the leaves are removed (except a few at the top), and the tree is decorated with red paper. Red has long been associated with warding off evil spirits. The Cay Neu is taken down on the seventh day of Tet.
Deceased relatives are also remembered during Tet. Families build alters with photographs, flowers, incense, money and food. People typically visit the gravesites of deceased loved ones.
GIAO THUA is the transition moment between the old year and the New Year. It is one of the most important times during the TET holidays. It occurs at the midnight hour on New Year's Eve. Giao Thua is the time when a family ushers out the spirits of the old year, a ritual called LE TRU TICH. Drums, gongs and firecrackers announced the hour of LE GIAO THUA. The spirits of the old year are rushed out and the new spirits are welcomed. The streets are chaotic with everyone banging gongs and sounding off all sorts of noisemakers to scare away evil spirits.

At Giao Thua, everyone in the family gather together to pray, to congratulate the New Year and to wish each other the very bests for the coming year; the oldest set of parents (usually the grandparents) are congratulated and offered best wishes first, then the order is trickled down!

At mid-morning, the visiting starts, people filling the streets. The first day of Tet is reserved for visiting family and relatives, the second day for special guests and close friends, and the third day for teachers, friends and business associates. The first visitor of the year to a house is the most significant, being a portent of the coming year's fortune. Particular care is taken to arrange in advance to have the visitor be rich, happy, and prestigious. Usually, it is a member of the family or a relative, but sometimes a special guest may be invited if he or she is considered to be a lucky person. After the initial greeting, visitors are served candied fruits and dried watermelon seeds. Tea, coffee, beer, champagne or whiskey are also offered, as well as more substantial fare, such as banh chung or banh Tet, spring rolls or a pate-like sausage. Pickled green onions are a universal snack, especially when drinking. One belief is that when a watermelon is cut open the redder the flesh the more luck the family will have in the New Year.

There are many pleasantries exchanged, and everyone is on his best behavior. Negative talk is a taboo, as the attitude of the first few days of the New Year sets the tone for the remainder of the year. Gambling is also a favorite after midnight activity, and continues for the three days of Tet and beyond.

Children are especially favored. They receive a "li xi", or lucky money, in red envelopes from their parents, older relatives and older friends. Even their older siblings give them li xi.

Tet officially lasts for seven days and ends with LE KHAI HA ritual during which CAY NEU is taken down.

While many Asian people today may not believe in these do's and don'ts, these traditions and customs are still practiced. They are kept because most families realize that these very traditions, whether believed or not, provide a continuity with the past and support the family with an identity.