Lunisolar Calendar

The calendar is lunisolar: months follow the waxing and waning of the moon, and intercalation reconciles them with the cycle of the sun. Oracle bones from Yinxu record twelve months with an interposed "thirteenth month", which shows that the Shang already used a lunisolar calendar. Emperor Wu of Han issued the Taichu calendar, making the first month the head of the year and fixing the basic shape of the later lunar calendar. In the early Qing the Shixian calendar was issued, using the true-solar-term method, and became the direct basis of today's lunar calendar.

The festivals are mostly fixed by month and day: the Spring Festival on the first day of the first month, the Lantern Festival on the fifteenth, the Dragon Raises Its Head Festival on the second day of the second month, the Double Third on the third day of the third month, the Dragon Boat Festival on the fifth day of the fifth month, Qixi on the seventh day of the seventh month, Zhongyuan on the fifteenth, the Mid-Autumn Festival on the fifteenth day of the eighth month, the Double Ninth on the ninth day of the ninth month, the Cold Clothes Festival on the first day of the tenth month, Laba on the eighth day of the twelfth month, the Little New Year on the twenty-third or twenty-fourth of the twelfth month, and New Year's Eve at the year's end. The Cold Food Festival and She Day are not set by month and day but counted on: the Cold Food Festival falls one hundred and five days after the winter solstice, and She Day on the fifth wu day after Beginning of Spring or Beginning of Autumn.

Each festival has its own customs: the Spring Festival has the family reunion and night vigil on New Year's Eve and New Year visits on the first day; the Dragon Boat Festival has dragon-boat racing and eating zongzi; the Mid-Autumn Festival has moon-gazing and mooncakes; the Double Ninth has climbing high and drinking chrysanthemum wine; and Laba has the cooking of porridge.