Tang Minh Ly, a 38-year-old former Navy warrant officer from Vietnam, is looking forward to his most "lighthearted and relaxed" lunar new year holiday in six years--although it will also be his first away from home.

The new year observance, called Tet, will begin Monday and is the most important holiday for the Vietnamese people.

A year ago Ly was deep in preparations for a perilous escape from Vietnam. Ten days after the Tet holiday began in 1981, Ly, with his wife, two small children, now 6 and 8, and 75 of their countrymen, fled by boat with Ly at the helm.

Now, he says, "I'm very excited about my first Tet in the United States. It certainly does not match the one in my homeland. I have to face some difficulties in my new life here. But for me this is the most lighthearted and the most relaxed Tet since the Communist takeover of South Vietnam.

"But whatever joy I have here, I still miss my parents in Vietnam and my homeland," he added.

Because of its emphasis on the gathering of the extended family and honoring ancestors, Tet can be a painful time for refugees who are alone in this country. Nguyen Quang Trung, a 25-year-old bachelor, said he and his younger brother have "no relatives and a few friends here." The two men share a room on Woodley Road in the District.

"For me the holiday is not much different from a regular day. I do not prepare anything for Tet. Neither do I for American holidays," said Quang, who added that he and his brother "sometimes travel on holidays."

For the nearly 15,000 Vietnamese living in the Washington area, Tet marks everyone's birthday as well as the new year. It is a time of celebration and the welcoming of spring, as well as the season for families to visit and care for the ancestral graves. Of deeper significance, Tet is dominated by the firmly rooted concepts of fortune and propitiation of the gods and the ancestors.

Calculated according to the lunar rather than the Gregorian calendar, the first day of the new year always falls sometime between late January and early February. Each year is assigned to one of the 12 animal symbols of the Vietnamese zodiac, arriving in this order: mouse, buffalo, tiger, cat, dragon, snake, horse, goat, monkey, rooster, dog and pig. Next Monday will usher in the year of the dog.

Because of its deep spiritual significance, Tet is the time when Vietnamese refugees here most long for home, and when many pay special attention to traditions and rituals.

Seven days before Tet, a food offering is made to the kitchen god, who will make his annual report to the Jade Emperor of the universe, according to legend. Custom calls for the entire extended family to congregate at the family altar on the first day of Tet to thank their forebears for their existence, and request the traditional blessings of happiness, prosperity and longevity.

Superstitions connected with the holiday abound. Many seem to have sprung from a need to live in harmony with one's family, friends and environment. Before Tet, debts must be paid off, mistakes forgotten, offenses pardoned and faults corrected. Hospitality and friendship must dominate the three-day celebrations, and conflict and anger must be avoided.

Because what happens on the first day of Tet is thought to affect the coming year, many Vietnamese observe traditional taboos. No one must visit another's home on the first day of Tet unless asked, because that initial visitor is thought to determine the luck--or misfortune--for the host family during the entire year.

During Tet, each person wears new clothes, and good wishes are exchanged. Gifts of new money carefully folded in specially made small red envelopes are believed to bring good luck during the year.

Although most of these customs are maintained by Vietnamese residents here, the ways of celebrating have changed somewhat.

Area Vietnamese residents have planned a number of public events to celebrate the Tet holiday that began earlier this month and will continue through the first day of the new year, Monday.

The Council of Vietnamese Associations has planned an arts festival, a Vietnamese movie showing, a poetry contest, a special broadcast, a fair and a reception. A shipment of magazines and money also has been sent to refugees still in Southeast Asian camps. The Vietnamese Navy Veterans Association, the Vietnamese Lawyers Association and other groups have held parties and dances.

New Year events for the remainder of the month:

Tet Fair, Cafeteria, Kenmore Intermediate School, Arlington, Saturday, 10 a.m. to 5 p.m.

Vietnamese Folk Opera, Fairfax High School, Fairfax, Saturday, 7 p.m.

Tet Fair, Montgomery Blair High School, Silver Spring, Saturday, 10 a.m. to 3 p.m.

Cultural performance, Montgomery Blair High School, Silver Spring, Saturday, 3 p.m.

Traditional service in honor of the ancestors, Kenmore Intermediate School, Arlington, Saturday, Jan. 30, 11 a.m.

Radio broadcasts welcoming the new year, Sunday:

WHFS, FM 102.3: (in Vietnamese). 9-10 p.m.

WETA, FM 90.9: (in English). This broadcast is to introduce the Tet customs to the local American community, followed by an interview with four Vietnamese community leaders. 11:30 p.m. to midnight.

WETA, FM 90.9: (in Vietnamese). Special New Year's Eve broadcast. Midnight to 1 a.m.

Vu Thuy Hoang is a Washington Post library staff member. Diana G. Bui is with the Indochinese Community Center in the District.