For billions of Chinese around the world (not to mention millions of Vietnamese, who call it Tet, and Koreans, who call it Sol Nal), today is the first day of the new lunar year — the year of the Water Snake, according to astrological tradition.

In China, Lunar New Year's Day marks the beginning of Spring Festival, the most important holiday in the traditional calendar. This weekend, hundreds of millions of students, urban transplants and migrant laborers are crowding airports and clogging train stations in desperate attempts...