立春 is the first and arguably one of the most important of the 二十四节气 (èrshísì jiéqì), the 24 Solar Terms. This traditional Chinese calendar system, recognized as a UNESCO Intangible Cultural Heritage, is based on the sun's position on the ecliptic and was the essential guide for agriculture for millennia. A key cultural point of contrast is with the Western concept of spring. In the West, the “first day of spring” is the Spring Equinox (around March 20th). In the Chinese system, the equinox is called 春分 (chūnfēn) and is considered the midpoint of spring, when day and night are of equal length. 立春, occurring much earlier (around Feb 4th), is the true beginning. This reflects a philosophical view of seeing seasons not as static states, but as a gradual process of waxing and waning energies (Yin and Yang). Traditional customs associated with 立春 include:
While no longer a public holiday, 立春 remains a widely recognized day.