Tet Nguyen Dan or simply Tet is Vietnamese New Year celebration according to the Vietnamese Lunar calendar that differs from Western calendars significantly. Most often the holiday falls in February and thus it also marks the arriving of spring, which of course doubles the joy. Vietnamese take the holiday seriously, and there are sets of typical ceremonies as well as typical foods one should eat during Tet, which itself can also last for seven days.
People usually clean their homes before the feast, decorate the houses with bamboo plants and peach blossoms and perform all kinds of religious rituals. The colour of the feast is red since it is believed to bring good luck and prosperity. Several days of celebration are dedicated to certain issues. For example, the first day would be dedicated to the Kitchen Gods, the second day—to the preparation of the special Tet delicacies called Bahn Chung, next day could be dedicated to family reunions, and so on.
When you plan your visit to Vietnam during Tet, keep in mind that the festivities are taking a lot of local people's time and some services might be unavailable. However, you can prolong your trip and do some hiking around the northern regions, where nature starts to awake and bloom to celebrate spring as well.