See caption
2017 Chinese calendar
Page of a Chinese calendar

The traditional Chinese calendar (officially known as the Agricultural Calendar [農曆; 农历; Nónglì; 'farming calendar']), Former Calendar (舊曆; 旧历; Jiùlì), Traditional Calendar (老曆; 老历; Lǎolì) or Lunar Calendar (陰曆; 阴历; Yīnlì; 'yin calendar'), is a lunisolar calendar which reckons years, months and days according to astronomical phenomena. In modern days, it is defined in China by GB/T 33661-2017, "Calculation and promulgation of the Chinese calendar", issued by the Standardisation Administration of China on 12 May 2017.

Although modern-day China uses the Gregorian calendar, the traditional Chinese calendar governs holidays—such as the Chinese New Year and Lantern Festival—in both China and in overseas Chinese communities. It also gives the traditional Chinese nomenclature of dates within a year, which people use for selecting auspicious days for weddings, funerals, moving, or starting a business. The evening state-run news program Xinwen Lianbo in the P.R.C. continues to announce the month and date in both the Gregorian and the traditional lunisolar calendar.

Like Chinese characters, variants of this calendar are used in different parts of the East Asian cultural sphere. Korea, Vietnam, and the Ryukyu Islands adopted the calendar, and it evolved into Korean, Vietnamese, and Ryukyuan calendars. The main difference from the traditional Chinese calendar is the use of different meridians, which leads to some astronomical events—and calendar events based on them—falling on different dates. The traditional Japanese calendar also derived from the Chinese calendar (based on a Japanese meridian), but its official use in Japan was abolished in 1873 as part of reforms after the Meiji Restoration. Calendars in Mongolia and Tibet have absorbed elements of the traditional Chinese calendar, but are not direct descendants of it.[citation needed][1]

Days begin and end at midnight, and months begin on the day of the new moon. Years begin on the second (or third) new moon after the winter solstice. Solar terms govern the beginning and end of each month. A sexagenary cycle, consisting of stems (干) and branches (支), is used as identification alongside each year, month, including intercalary months or leap months as needed. The length of a month is also annotated as either long (大, literally "big" for months with 30 days) or short (小, literally "small" for months with 29 days).

History