Lichun, the Start of Spring, opens the cycle of twenty-four solar terms at the sun's celestial longitude of 315 degrees, around the fourth of February. It is a sectional (jie) term and traditionally the first term of the year, marking the point where winter yields to the earliest stirrings of spring. In the agricultural almanac it is the signal to prepare the fields and tools for the coming season, and it has long carried its own customs, the ceremonial welcoming of spring, the eating of spring pancakes, and the fashioning of a clay ox to encourage the plough. Because the solar terms track the sun rather than the moon, Lichun falls on nearly the same Gregorian date each year. These are the observances of the East Asian agricultural tradition, resting on the astronomical division of the tropical year into twenty-four equal solar arcs.
The twenty-four solar terms as a whole were inscribed on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity in 2016, recognising the system as a living body of agricultural and folk knowledge rather than only a technical astronomical scheme. Each term is traditionally further divided into three five-day hou, or pentads, giving seventy-two shorter divisions across the year, each historically assigned a description of a natural sign, an animal's behaviour, a plant's budding, drawn from texts such as the Yueling, the Monthly Ordinances chapter of the classical Book of Rites.