Ten Heavenly Stems and Twelve Earthly Branches

Short for Stem-Branch or Gan-Zhi, the Heavenly Stems and Earthly Branches are the most important counting system in the Chinese calendar. There are 10 Stems and 12 Branches.

The Ten Heavenly Stems are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren and Gui.

The Twelve Earthly Branches are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai.

From the unearthed inscriptions on bones of the Shang Dynasty (17th century BC - 1046 BC) of Yin Ruins, Gan-Zhi is used to record days as well as in Feng Shui and divination. Now, it’s not only applied for counting hour, day, month and year but also greatly used in Chinese astrology for fortune-telling.

The 10 stems, each is paired with an earthly branch forming a 60-Year Cycle which is a cycle of sixty terms and used for recording days, months and years. It starts with Jia-Zi and ends with Gui-Hai. Hereunder is the match of Stems and Branches. The rule is that the Yang Heavenly Stems match the Yang Earthly Branches, and the Yin Stems match the Yin Branches (get to know The Relationship between the Stem-Branch and Yin/Yang).

On Chinese calendars and almanacs, you can see this kind of note: e.g. For May 1, 2015, the calendar shows - March 13, Yi Wei (Sheep) Year (2015), Ding Chou Day, Geng Chen Month. This is the use of the Heavenly Stems and Earthly Branches. It’s used for recording the year, month and day. Hereunder is how to calculate the year and month:

Calculate the year: As you can see from the Chinese calendar, 2015 is Yi Wei Year. To get this, follow the steps below:

1. 2015 - 3 = 2012 ('subtracting 3 from the Gregorian year')
2. 2012 ÷ 60 = 33 ('divide by 60 and discard any fraction')
3. 2012 - (60 × 33) = 32 ('taking the remainder')
4. Look for 32 from the above table and we get Yi-Wei for the year of 2015.

Find the zodiac animal of the year:
In Chinese culture, each of the Earthly Branch has a corresponding animal. Following is the relationship between the Earthly Branch and Chinese Zodiac Animals:
As we already know 2015 is Yi-Wei year. Wei is the earthly branch for 2015, check Wei in the above table, we know that the corresponding zodiac animal is Sheep. So, 2015 is year of the Sheep.

Calculate the month:
Hereunder is the relationship between the stem of the year and the stem of the month. Take 2015 for example, as we already know Yi is the Heavenly Stem for 2015, we can get January is Wu-Yin, Februay is Ji-Mao, March is Geng-Chen…from the following table. Please note that the month hereunder refers to the Chinese lunar month. You can use our Gregorian-Chinese Calendar Converter on the Chinese calendar page to get the Chinese lunar month.

The 12 earthly branches not only stand for 12 Chinese animals but also 12 hours. In the old times, there was no conception of 24-hour for a day. People divided a day into 12 Shichen. Hereunder is the relationship between 12 Shichen and the present time system:

12 shichen	The present time
Zi hour	23:00-01:00
Chou hour	01:00-03:00
Yin hour	03:00-05:00
Mao hour	05:00-07:00
Chen hour	07:00-09:00
Si hour	09:00-11:00
Wu hour	11:00-13:00
Wei hour	13:00-15:00
Shen hour	15:00-17:00
You hour	17:00-19:00
Xu hour	19:00-21:00
Hai hour	21:00-23:00

Note:
Yin: negative/passive/female principle in nature
Yang: positive/active/male principle in nature