Which calendar system determines the Chinese New Year date, which can place Lunar New Year in January or February?

The Chinese lunisolar calendar determines the Chinese New Year date, which can place Lunar New Year in January or February.

The traditional Chinese calendar combines lunar months with a solar year. Months begin at new moons, but the calendar also uses solar terms and occasional intercalary months to keep lunar dates aligned with the seasons. Chinese New Year therefore does not fall on a fixed Gregorian date.

The festival begins on the first day of the first month of the traditional calendar. In the Gregorian calendar, that date falls between January 21 and February 20, inclusive, depending on the year. The celebration lasts fifteen days and concludes with the Lantern Festival.

The Chinese calendar is not simply a lunar calendar: a purely lunar system would drift through the seasons. It is also not the Gregorian calendar used for the international civil date. The term lunisolar captures the combination of lunar months and solar adjustment, while regional communities may use related traditional calendars with different names or observances.