What calendar system determines the date of Chinese New Year, which may fall in January or February?

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

The festival begins on the first day of the first month of the traditional Chinese calendar. Because that calendar combines lunar months with adjustments tied to the solar year, the date shifts annually when converted to the Gregorian calendar. Chinese New Year therefore does not have one fixed Gregorian date.

The celebration is also called the Spring Festival, or Chun Jie in Mandarin. It begins a new year in the traditional calendar and is marked by family reunions, special foods, red decorations, gifts, and public performances. The holiday period is among the most important annual observances for Chinese communities.

Chinese New Year is often casually treated as the same event as January 1, but the two follow different calendar systems and occur weeks apart in many years. Other East and Southeast Asian New Year celebrations may use related lunisolar calculations, yet local customs and names are not identical.