Civil hour reference · 1990-08-27 · 09:00–11:00
August 27, 1990 · 09:00–11:00 (Si hour · Snake)
The Si hour · Snake double-hour (09:00–11:00) completes Monday, August 27, 1990 with a fourth, hour pillar: 庚午 · 甲申 · 甲子 · 己巳.
Answer first: the reference four pillars for 1990-08-27, 09:00–11:00, are year 庚午, month 甲申, day 甲子, hour 己巳. The hour stem is derived from the day stem by the standard five-rat rule. This is a deterministic calendar record, not a personal reading.
Deterministic record
1990-08-27 · 09:00–11:00 at a glance
| Gregorian date | Monday, August 27, 1990 |
|---|---|
| Double-hour | Si hour · Snake · 09:00–11:00 civil clock · branch 巳 |
| Year pillar | 庚午 · Yang Metal Horse · Yang Metal over Fire |
| Month pillar | 甲申 · Yang Wood Monkey · Yang Wood over Metal |
| Day pillar | 甲子 · Yang Wood Rat · Yang Wood over Water |
| Hour pillar | 己巳 · Yin Earth Snake · Yin Earth over Fire |
| Hour Na Yin | 大林木 · hidden stems 丙 · 庚 · 戊 |
| Zi-hour convention | Early Zi: the 23:00–01:00 double-hour is anchored to this civil date at 00:00. The late-Zi school (23:00–24:00 → next day) is a documented boundary below. |
Four coordinates, four jobs
What the four reference pillars contain
Each stem-branch pair is a deterministic calendar coordinate. The hour pair inherits its branch from the double-hour and its stem from the day stem, so it stays consistent with every other hour page of this date.
Yang Metal Horse · Geng Wu
The visible stem is Geng · Yang Metal; the branch is Wu · Horse · Fire. Its Na Yin is 路旁土, and the branch contains hidden stems 丁 · 己. Open the full Jiazi record →
Yang Wood Monkey · Jia Shen
The visible stem is Jia · Yang Wood; the branch is Shen · Monkey · Metal. Its Na Yin is 泉中水, and the branch contains hidden stems 庚 · 壬 · 戊. Open the full Jiazi record →
Yang Wood Rat · Jia Zi
The visible stem is Jia · Yang Wood; the branch is Zi · Rat · Water. Its Na Yin is 海中金, and the branch contains hidden stem 癸. Open the full Jiazi record →
Yin Earth Snake · Ji Si
The visible stem is Ji · Yin Earth; the branch is Si · Snake · Fire. Its Na Yin is 大林木, and the branch contains hidden stems 丙 · 庚 · 戊. Open the full Jiazi record →
Calculation boundary
What this hour reference does not settle
This page uses a standard civil clock so double-hours can be compared consistently across dates. A real birth happened at a place and an instant, not inside a URL slug.
- True solar time: the reference assumes a standard-meridian civil clock. Birthplace longitude and the equation of time shift the effective hour, and can move the resolved pillar to a neighboring double-hour.
- Hour boundary: a clock time within the correction margin of an odd-hour boundary (09:00 or 11:00) is boundary-risk until resolved against place.
- Zi-hour school: the 23:00–01:00 slot follows the early-Zi convention. Late-Zi schools push 23:00–24:00 onto the next day pillar; neither this page nor the atlas settles that debate.
- Interpretation: one four-pillar record does not determine personality, career, relationships, wealth, health, or events. It is a coordinate, not a verdict.
All twelve double-hours of 1990-08-27
Resolve your actual hour pillar
Calculate the real birth chart
Add birth time and birthplace. Pillarwise resolves historical timezone, longitude correction, equation of time, and hour-boundary risk before it fixes the hour pillar — this reference page is only the civil-clock starting point.
Questions about 1990-08-27 09:00–11:00
What is the hour pillar for 09:00–11:00 on Monday, August 27, 1990?
In this civil-clock reference, the 09:00–11:00 double-hour on 1990-08-27 carries the hour pillar 己巳 (Yin Earth Snake), completing the four-pillar record 庚午 · 甲申 · 甲子 · 己巳.
Why does the Zi hour list 23:00–01:00 as one range?
The Zi double-hour spans midnight in the classical two-segment form 23:00–01:00. This reference adopts the early-Zi convention: 00:00–01:00 belongs to the same civil date. Schools that use the late-Zi convention assign 23:00–24:00 to the next day pillar, which can change both the day and hour pillar; that difference is an open school boundary, not an error.
Is this my personal hour pillar?
Not necessarily. This page is a civil-clock reference at a standard meridian. A personal chart resolves your birthplace longitude, historical timezone, and true solar time, and any of those corrections can move the resolved hour pillar to a neighboring double-hour.
What happens near an hour boundary?
A clock time within the correction margin of an odd-hour boundary (01:00, 03:00, … 23:00) can resolve to the adjacent double-hour once longitude and equation-of-time corrections are applied. Use the calculator to see the resolved pillar and its boundary-risk flag.