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Meaning and Context
The Ten Heavenly Stems cycle through days, with each day having one stem. Combined with Earthly Branches, they form the 60-day cycle that repeats throughout the calendar.
- Tian (天): Heaven, celestial
- Gan (干): Stem, trunk
- 10 stems: 甲乙丙丁戊己庚辛壬癸 (Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui)
- Each paired with a Five Element and yin/yang polarity
Classical Roots
From Xieji Bianfang Shu
「天干配日，主气之所向，择日先察天干。」
Plain translation
"Heavenly Stems correspond to days, directing the flow of qi — in date selection, first examine the stem." Stems set the day's primary energy.
The Ten Stems and Their Elements
Each stem with its element and polarity:
- 甲 (Jia): Yang Wood
- 乙 (Yi): Yin Wood
- 丙 (Bing): Yang Fire
- 丁 (Ding): Yin Fire
- 戊 (Wu): Yang Earth
- 己 (Ji): Yin Earth
- 庚 (Geng): Yang Metal
- 辛 (Xin): Yin Metal
- 壬 (Ren): Yang Water
- 癸 (Gui): Yin Water
How It Shows Up in FateFolio
In FateFolio's date selection, the daily heavenly stem is displayed as part of the Gan Zhi date marking. This stem indicates the day's primary elemental quality.
Common Misconceptions
- Thinking stems alone determine day quality — branches matter equally
- Ignoring stem combinations — certain stem pairs have special properties
- Confusing with the branch zodiac — stems represent different qualities
FAQ
How do stems differ from branches in date selection?
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Stems represent the "heavenly" or yang aspect of timing, while branches represent the "earthly" or yin aspect. Stems cycle in 10s (repeating every 10 days for that component), while branches cycle in 12s. Together they create the 60-day cycle. Both are considered in date selection, with stems often indicating the day's primary elemental character.