Lunar New Year, Chinese Chunjie, Vietnamese Tet, Korean Solnal, and Tibetan Losar, also called Spring Festival, the festival typically celebrated in China and other Asian countries that begins with the first new moon of the lunar calendar and ends on the first full moon of the lunar calendar, 15 days later. The lunar calendar is based on the cycles of the moon, so the dates of the holiday vary slightly from year to year, beginning sometime between January 21 and February 20, according to Western calendars.