Earthly Branches

The Earthly Branches (Chinese and Japanese: 地支; pinyin: dìzhī; Korean: 지지; or Chinese and Japanese: 十二支; pinyin: shí'èrzhī; Korean: 십이지; literally: "twelve branches") provide one Chinese system for reckoning time.

This system was built from observations of the orbit of Jupiter. Chinese astronomers divided the celestial circle into 12 sections to follow the orbit of 歲星 Suìxīng (Jupiter, the Year Star). Astronomers rounded the orbit of Suixing to 12 years (from 11.86). Suixing was associated with 攝提 Shètí (η Boötis) and sometimes called Sheti.

In correlative thinking, the twelve years of the Jupiter cycle also identify the twelve months of the year, twelve animals (mnemonics for the system), directions, seasons, and Chinese hour in the form of double-hours. When a Branch is used for a double hour, the listed periods are meant. When used for an exact time of a day, it is the center of the period. For instance, 午 (the Horse) means noon or a period from 11am to 1pm. (The jie qi system provided single hours and 15-degree arcs in time and space.)

Chinese seasons are based on observations of the sun and stars. Many Chinese calendrical systems have started the new year on the second new moon after the winter solstice.

The Earthly Branches are today used with the Heavenly Stems in the current version of the "traditional Chinese calendar" and in Taoism. The Ganzhi (Stem-Branch) combination is a fairly new way to mark time; in the second millennium BC, during the Shang era, it was the ten Heavenly Stems that provided the names of the days of the week. The Branches are as old as the Stems (and according to recent archaeology may actually be older), but the Stems were tied to the ritual calendars of Chinese kings. They were not part of the calendrical systems of the majority of Chinese.

The twelve branches

Some cultures assign different animals: Vietnam replaces the Ox and Rabbit with the water buffalo and cat respectively; Japan replaces the Pig (豚) with the boar (猪); Tibet replaces the Rooster with the bird. In the traditional Kazakh version of the 12-year animal cycle (Kazakh: мүшел, müşel), the Dragon is substituted by a snail (Kazakh: ұлу, ulw), and the Tiger appears as a leopard (Kazakh: барыс, barıs).^[1]

Directions

The 24 cardinal directions (ancient Chinese convention places the south (red) at the top).

Even though Chinese has words for the four cardinal directions, Chinese mariners and astronomers/astrologers preferred using the twelve directions of the Earthly Branches, which is somewhat similar to the modern-day practice of English-speaking pilots using o'clock for directions. Since twelve points were not enough for sailing, twelve midpoints were added. Instead of combining two adjacent direction names, they assigned new names as follows:

• For the four diagonal directions, appropriate trigram names of I Ching were used.
• For the rest, the Heavenly Stems were used. According to the Five Elements theory, east is assigned to wood, and the Stems of wood are 甲 (jiǎ) and 乙 (yǐ). Thus they were assigned clockwise to the two adjacent points of the east.

Following is a table of the 24 directions:

Advanced mariners such as Zheng He used 48-point compasses. An additional midpoint was called by a combination of its two closest basic directions, such as 丙午 (bǐngwǔ) for the direction of 172.5°, the midpoint between 丙 (bǐng), 165°, and 午 (wǔ), 180°.

See also

• Sexagesimal cycle (干支)
• Sheng Xiao
• Celestial stem
• Chinese calendar
• (A study of the cardinal directions chart)

References

External links

• Heavenly Stems and Earthly Branches - Hong Kong Observatory

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