Qīngmíng

Qingming, Clear and Bright, is the fifth solar term, at the sun's longitude of 15 degrees, around the fifth of April. It is a sectional (jie) term and, uniquely among the twenty-four, also a major festival. The Qingming Festival, or Tomb-Sweeping Day, is when families visit and tidy the graves of their ancestors, make offerings, and honour the dead, while the bright spring weather draws people outdoors to walk and fly kites. Its name describes the clear, bright freshness of the season, when the fields are green and the air is mild. In the farming almanac it is the time for the main spring sowing. Being a solar marker, it falls near the same Gregorian date each year. These are the observances of a living East Asian tradition, resting on the solar-term division of the tropical year.

Qingming, the Clear and Bright term, falls at 15 degrees, around 4 or 5 April, and is a jie, or sectional, term, distinctive among the twenty-four for having become a major public festival in its own right, Tomb-Sweeping Day, a public holiday in mainland China, Taiwan and Hong Kong on which families visit and clean ancestral graves, make offerings of food and burn joss paper. The festival's association with this specific solar term, rather than with a fixed lunar date, reflects Qingming's origin as an agricultural marker for clear skies and warming soil suited to spring planting, a practical meaning that coexists with, but is historically distinct from, the ancestral-veneration customs later attached to the same date, which some scholars trace to an older cold-food festival, Hanshi, observed shortly before it.

The twenty-four solar terms divide the ecliptic into equal arcs of fifteen degrees, and this one falls at 15 degrees of the sun's apparent longitude. It is a sectional term, a jie, one of the twelve that fall in the odd positions of the twenty-four and open the twelve solar months. The sectional terms and the major terms alternate strictly around the year, so a jie is always followed by a zhong fifteen degrees later.

The terms have not always been spaced the same way. Until the seventeenth century they were reckoned by equal intervals of time, dividing the year into twenty-four equal parts, a method called pingqi. The Shixian calendar, prepared with Jesuit assistance and promulgated in 1645, redefined them by equal intervals of the sun's apparent longitude instead, fifteen degrees apart, which is the definition still used. Because the Earth's orbit is elliptical the sun does not move at a uniform apparent rate, so the intervals between terms now vary by about a day between the shortest and the longest.

Qingming is the only one of the twenty-four terms that is also a major festival. Tomb sweeping, the tending of family graves and offerings to ancestors fall on it, and it is a public holiday in mainland China, Taiwan and Hong Kong. The festival and the solar term have converged over a long period, absorbing an older observance, the Cold Food festival, that fell immediately before it, and the two are now generally treated as one occasion.