Gui Water Day Master (癸): the Yin Water stem in BaZi
Last checked · verse from the Di Tian Sui on Chinese Wikisource; tables calculated
癸 (Gui) is the tenth Heavenly Stem, the yin partner of 壬 Ren in water. The Di Tian Sui opens its verse with "Gui water is the weakest of all, yet it reaches the Heavenly Ford (天津, a star group in Cygnus)", and its annotation describes Gui as pure yin and the weakest stem.
Stem
癸 Gui
Element and polarity
Yin Water
Combines with
戊 Wu (Fire)
Clashes with
丁 Ding
The Gui verse in the Di Tian Sui (滴天髓)
Verse traditionally attributed to Jingtu (京圖), with the annotation attributed to Liu Ji (劉基, Ming dynasty); quoted from Chinese Wikisource. The translation is ours.
癸水至弱，達於天津，龍德而運，功化斯神，不畏火土，不論庚辛，合戊見火，火根乃真。
Gui water is the weakest of all, yet it reaches the Heavenly Ford (天津, a star group in Cygnus). Moving with the virtue of the dragon, its work of transformation becomes wondrous. It fears neither fire nor earth, and pays no heed to Geng or Xin. When it combines with Wu, it must meet fire; only with a root of fire is the change true.
The verse uses human words (kind, loyal, filial) for how the stems act on one another in a chart; it does not describe people.
What the annotation says
Gui is pure yin and the weakest stem, yet it reaches the Heavenly Ford. Wherever Jia, Yi, 寅 or 卯 appear, it moves the qi of water: it feeds wood, checks fire, moistens earth and nourishes metal, as a dragon moves water. It does not depend on Geng and Xin, nor mind how many there are. When it combines with Wu to become fire, there must be a fire root for the change to be real.
The annotation opens with 「癸乃純陰而至弱，然上達天津」 (pure yin and the weakest stem). Summarized in our words from the annotation on the same 天干論 page on Wikisource.
Water in the Huainanzi (淮南子)
The Huainanzi, 天文訓 chapter, lists each direction with its element, season, planet and animal, and ends with the two stems of its days.
北方，水也……執權而治冬。其神為辰星，其獸玄武，其音羽，其日壬癸。
Direction: North · Season: Winter · Planet: Mercury (辰星) · Animal: Black Tortoise (玄武, the Dark Warrior) · Note: yu (羽)
Ten Gods for a Gui Water Day Master
What each of the ten stems is called, seen from this Day Master.
| Stem | Element | Ten God | Chinese |
|---|---|---|---|
| 甲 Jia | Yang Wood | Hurting Officer | 伤官 Shang Guan |
| 乙 Yi | Yin Wood | Eating God | 食神 Shi Shen |
| 丙 Bing | Yang Fire | Direct Wealth | 正财 Zheng Cai |
| 丁 Ding | Yin Fire | Indirect Wealth | 偏财 Pian Cai |
| 戊 Wu | Yang Earth | Direct Officer | 正官 Zheng Guan |
| 己 Ji | Yin Earth | Seven Killings | 七杀 Qi Sha |
| 庚 Geng | Yang Metal | Direct Resource | 正印 Zheng Yin |
| 辛 Xin | Yin Metal | Indirect Resource | 偏印 Pian Yin |
| 壬 Ren | Yang Water | Rob Wealth | 劫财 Jie Cai |
| 癸 Gui | Yin Water | Friend | 比肩 Bi Jian |
Twelve stages of Gui (长生十二宫)
A yin stem runs backward through the branches from its Growth stage.
| Branch | Animal | Stage |
|---|---|---|
| 卯 Mao | Rabbit | 长生 Growth |
| 寅 Yin | Tiger | 沐浴 Bath |
| 丑 Chou | Ox | 冠带 Cap and Belt |
| 子 Zi | Rat | 临官 Taking Office |
| 亥 Hai | Pig | 帝旺 Prosperity |
| 戌 Xu | Dog | 衰 Decline |
| 酉 You | Rooster | 病 Sickness |
| 申 Shen | Monkey | 死 Death |
| 未 Wei | Goat | 墓 Tomb |
| 午 Wu | Horse | 绝 Extinction |
| 巳 Si | Snake | 胎 Conception |
| 辰 Chen | Dragon | 养 Nurture |
The six Gui day pillars
Gui pairs only with the yin branches, so it appears in six of the sixty pillars.
| Pillar | No. in the cycle | Na Yin | Void branches |
|---|---|---|---|
| 癸酉 Gui You | 10 | 剑锋金 Sword Metal | 戌亥 |
| 癸未 Gui Wei | 20 | 杨柳木 Willow Wood | 申酉 |
| 癸巳 Gui Si | 30 | 长流水 Long River Water | 午未 |
| 癸卯 Gui Mao | 40 | 金箔金 Gold Leaf Metal | 辰巳 |
| 癸丑 Gui Chou | 50 | 桑柘木 Mulberry Wood | 寅卯 |
| 癸亥 Gui Hai | 60 | 大海水 Great Sea Water | 子丑 |
Gui is also a hidden stem in 子 Zi (as the main stem), 丑 Chou and 辰 Chen.
Next Gui days
China Standard Time dates; one day in every ten.
- Oct 26, 2026 · 癸酉
- Nov 5, 2026 · 癸未
- Nov 15, 2026 · 癸巳
- Nov 25, 2026 · 癸卯
- Dec 5, 2026 · 癸丑
- Dec 15, 2026 · 癸亥
FAQ
How do I find out if my Day Master is Gui Water?
Your Day Master is the stem of your day pillar. Enter your birth date, time and time zone in the BaZi calculator; if the day pillar starts with 癸, your Day Master is Gui.
What is a Gui Water Day Master?
A BaZi chart whose day pillar has 癸 (Gui) as its stem. Gui is the tenth of the ten Heavenly Stems, the yin stem of water. The Di Tian Sui annotation describes it as pure yin and the weakest stem (癸乃純陰而至弱，然上達天津).
What is the difference between Gui and Ren?
Both are water. Gui (癸) is the yin stem and Ren (壬) the yang one. The Di Tian Sui annotation describes Gui as pure yin and the weakest stem and Ren as the source of Gui water, which is both the hundred rivers and the rain and dew. Gui combines with Wu and Ren with Ding.
Which stem combines with Gui, and which clashes with it?
Gui combines with 戊 Wu (the 戊癸 combination, associated with Fire). It clashes with 丁 Ding.
How common is a Gui Day Master?
The day stems repeat every ten days without a break, so exactly one day in ten is a Gui day. The next ones are Oct 26, 2026, Nov 5, 2026, Nov 15, 2026 (China Standard Time dates).
Where does Gui sit in the twelve stages?
In the usual twelve-stage table, Gui has its Chang Sheng (Growth) in 卯 Mao and its Di Wang (Prosperity) in 亥 Hai; as a yin stem it moves backward through the branches.
Other Day Masters
Sources: 滴天髓 (Di Tian Sui), 天干論, on Chinese Wikisource; 淮南子 (Huainanzi), 天文訓, on Chinese Wikisource; Ten God names as in 淵海子平 (Yuan Hai Zi Ping) on Chinese Wikisource. This page describes the traditional system and quotes classical texts; it is not a character reading, a prediction or advice. Terms are given in simplified characters; quotations keep the script of their source. Day pillars: how they are calculated and checked.