The traditional new years in Vietnam (Tet) and in Korea (Korean New Year) are almost always on the same day as Chinese New Year but are sometimes different. The Japanese New Year used to work the same way but has been very different since some changes in the 19th century. Losar and Tsagaan Sar, the traditional Tibetan and Mongolian new years, are very close to the Chinese New Year but different ways of thinking about the moon's changes and adding months can make them happen weeks apart from the Chinese festival.