Answer: Tet is the native name for the Vietnamese New Year. This occasion falls on the first day of the lunisolar calendar; the Chinese and Koreans also use this calendar. The Vietnamese welcome in the New Year by simultaneously lighting up firecrackers at midnight time. This practice, however, was recently banned in Vietnam due to the dangers associated with it.
The significance of Tet comes from the fact that age (in Eastern culture) is determined by the first day of the year rather by birth date. In effect, all Vietnamese unofficially turn one year older on Tet making this the birthday of the entire population. People celebrate this event by dressing up their homes, offering to one another happy greetings, and giving away lucky packets or red envelopes. Celebrations for the Vietnamese New Year generally last for two weeks, with the first three days being the most important.