Yin Fire Snake (Ding Si, 丁巳) day pillar
A Yin Fire day master, the Candle, sitting on the Snake.
Your day pillar is the pair of characters for the day you were born. The top one, the stem, is your day master — you. The bottom one, the branch, is what it sits on. The sixty pillars come round in turn, one a day, so about one person in sixty was born on a Ding Si day.
Its sound element: Earth in the Sand (Sha Zhong Tu, 沙中土)
The sixty pillars go in pairs, and each pair carries a sound element (Na Yin, 纳音) — an image, separate from the element of the stem. The classic San Ming Tong Hui (三命通会) describes each pillar by it:
Sodden earth; likes Fire, and the northwest.
土之沮，喜火及西北
What the Snake holds, and what it is to Yin Fire
Each branch holds one to three stems. The ones under your own day master are the closest things to you in the chart.
- Yang Fire (Bing, 丙), the main one — Rob Wealth (Jie Cai, 劫财). Same element, opposite polarity. A peer who takes rather than shares — the tradition reads it as what draws on your resources through people close to you.
- Yang Metal (Geng, 庚) — Direct Wealth (Zheng Cai, 正财). What you control, opposite polarity. Wealth held steadily — earned, kept, accounted for.
- Yang Earth (Wu, 戊) — Hurting Officer (Shang Guan, 伤官). What you produce, opposite polarity. Output with an edge on it. The name means it injures the Direct Officer (正官), which is why the tradition reads it as talent that does not sit well with authority.
A Ding Si day at each birth hour: San Ming Tong Hui (三命通会)
Two volumes of this classic go hour by hour, and at each hour say something about this exact day pillar. These are its sentences on a Ding Si day; what it says about the other five Yin Fire days is on the Yin Fire day master page. Hours are true solar time, not clock time.
Rat hour 23:00–01:00 · Yang Metal Rat (Geng Zi, 庚子)
spring strong, summer robust — both noble. Autumn and winter, ordinary. The four seasonal months, held in check to the mean, favourable. Rat (子) and Dragon (辰) running a western period, fourth or fifth grade.
春旺，夏强，俱贵。秋冬平常。四季月，制伏得中吉。子辰，行西运，四五品贵。
Ox hour 01:00–03:00 · Yin Metal Ox (Xin Chou, 辛丑)
nobility comes through a woman. Snake (巳), Rooster (酉), Ox (丑) and Monkey (申) in year or month, wealth strong producing the officer, wealth and rank. A Rabbit (卯) month, ordinary, though running that period is also noble. An Ox month with a southwestern period, greatly noble.
因阴人致贵。巳酉丑申年月，财旺生官，富贵。卯月平常，行此运亦贵。丑月，西南运，大贵。
Tiger hour 03:00–05:00 · Yang Water Tiger (Ren Yin, 壬寅)
Yin Fire (丁) dies at Tiger (寅), and Snake (巳) has no thought of producing; punished by Tiger besides, it has a beginning and no end. If it runs Metal and Water periods, glory and nobility. Tiger and Horse (午) in year or month, the self strong; Monkey (申), Rat (子) and Dragon (辰), the officer strong; Pig (亥), Rabbit (卯) and Goat (未), the Resource (印) strong — all may be called noble.
丁死于寅，巳无生意，又被寅刑，有始无终，若行金水运，荣贵。寅午年月，身旺；申子辰，官旺；亥卯未，印旺，俱可言贵。
Rabbit hour 05:00–07:00 · Yin Water Rabbit (Gui Mao, 癸卯)
born in an Ox (丑) month with a northern period, where Earth (土) is thick, favourable; on ground where Water is fine, second or third grade. Monkey (申) and Rooster (酉), using wealth, also favourable.
丑月生，北方运，土厚地方，吉；水秀之地，二三品贵。申酉，用财亦吉。
Dragon hour 07:00–09:00 · Yang Wood Dragon (Jia Chen, 甲辰)
cruel punishment, solitude and harm. Spring, the Resource (印), favourable. Summer and autumn ordinary. Winter, the officer strong. Pure Dog (戌) with Wood and Fire periods, an office in a cold post.
凶刑孤克。春印吉。夏秋平常。冬官旺。纯戌，木火运，官居冷职。
Snake hour 09:00–11:00 · Yin Wood Snake (Yi Si, 乙巳)
born in a Snake (巳) month again, the Reverse Clash (倒冲) — Pig (亥) and Yang Water (壬) as the officer; where no Water fills it in solid to break the pattern, it governs the fourth or fifth grade.
再生巳月，倒冲，亥壬为官，无水填实破格者，主四五品贵。
Horse hour 11:00–13:00 · Yang Fire Horse (Bing Wu, 丙午)
Yin Fire (丁)'s prosperity star (禄) is Horse (午) and Yang Fire (丙)'s prosperity star is Snake (巳) — the exchanged-the prosperity star pattern; with no Tiger (寅), Pig (亥) or Rat (子) character in the pillars, the writing conspicuous and noble.
丁禄午，丙禄巳，互换禄格，柱无寅亥子字，文章显贵。
Goat hour 13:00–15:00 · Yin Fire Goat (Ding Wei, 丁未)
the Flanked Prosperity (拱禄) pattern, noble. Where the year holds a Rat (子) character, the Horse (午) is the gate tower, and getting the embracing (拱) it is greatly noble. It dislikes the Void (空亡) filling it in solid. Where year and month see wealth, officer and Resource (印), all favourable: wealth, riches; officer and Resource, nobility.
拱禄格贵。年有子字，则午为阙门，得拱大贵。忌空亡填实。年月见财官印，俱吉；财，富；官印，贵。
Monkey hour 15:00–17:00 · Yang Earth Monkey (Wu Shen, 戊申)
if not noble then wealthy, though punishment and harm are not escaped. Born in summer, running a northwestern period, noble; autumn and winter, toil and hardship.
不贵即富，未免刑克。夏生，行西北运，贵，秋冬，劳苦。
Rooster hour 17:00–19:00 · Yin Earth Rooster (Ji You, 己酉)
Snake (巳), Rooster (酉) and Ox (丑) in year or month, wealth strong producing the officer, wealth and rank all his life. Pig (亥) and Rat (子) also favourable.
巳酉丑年月，财旺生官，终身富贵。亥子亦吉。
Dog hour 19:00–21:00 · Yang Metal Dog (Geng Xu, 庚戌)
Dragon (辰) and Snake (巳) months with Metal and Water periods, the censorate. Yin Water (癸) and Rat (子), Yang Water (壬) and Pig (亥) with a southern period, the highest grade. Pure Goat (未) with a northwestern period, third or fourth grade; the self strong and not running wealth and officer periods, ordinary, and as a monk or priest, pure and high.
辰巳月，金水运，风宪。癸子、壬亥，南方运，极品。纯未，西北运，三四品；身旺不行财官运，平常，为僧道清高。
Pig hour 21:00–23:00 · Yin Metal Pig (Xin Hai, 辛亥)
hour and day clash — grief over wife and children. If it carries Fire qi, born in autumn, running an eastern period, noble. A Yin Metal (辛) month getting Snake (巳) and Pig (亥), breaking the ancestors and conspicuously fine.
时日相冲，忧伤妻子。若通火气，秋生，行东运，贵。辛月得巳亥者，破祖显秀。
The Snake and the other animals
When the day branch meets these — in a year, a ten-year luck period, or someone else’s chart — the classics read it by these relationships.
- Clashes with
- Pig
- Pairs with (six harmony)
- Monkey
- In a trine with
- Ox, Rooster
- Punishment with
- Tiger, Monkey
- Harms
- Tiger
- Breaks
- Monkey
The next Ding Si days: 9 December 2026, 7 February 2027, 8 April 2027. It returns every sixty days.
Famous people born on a Ding Si day
- Tsung-Dao Lee Physicist · Nobel Prize in Physics, 1957
The Yin Fire day master · Before it: Bing Chen · After it: Wu Wu · All sixty day pillars