Qi Men Hour Chart Plotting From Solar Time: The Complete Guide

You want to cast a Qi Men Dun Jia hour chart. You have the date, the time, and the question. But the clock on your wall tells you the wrong time for divination purposes. The hour chart runs on solar time, not the standard time your phone displays. If you plot the chart using the wrong time, every palace, every door, and every star will be off by one position, and your reading will be unreliable. This guide walks you through the full process of converting to solar time and constructing an accurate hour chart from scratch.

You can learn the broader hour chart system from the Qi Men Hour Chart complete guide. This article focuses on the technical process of plotting: time conversion, stem and branch calculation, and the mechanical steps of placing symbols into the nine palaces. When you finish, you will be able to construct a chart manually and verify that any software-generated chart is correct.

Why Solar Time Matters in Qi Men Dun Jia

QMDJ was developed thousands of years before time zones and daylight saving existed. The system runs on the position of the sun, not on political clock time. Solar time tells you where the sun actually is in the sky, which determines the true energy pattern of the moment. Clock time is a social convention. Solar time is a physical reality.

The difference between clock time and solar time can be significant. If you live at the eastern edge of a time zone, solar noon might arrive thirty minutes before clock noon. If you live at the western edge, solar noon might come thirty minutes after. That gap means a chart plotted at 10am clock time could actually represent 9:30am or 10:30am solar time, depending on your location. And because each Chinese hour covers a two-hour block, a thirty-minute shift can push you into an entirely different hour branch, changing the ruling palace and the entire chart reading.

For practitioners in Singapore, the difference is relatively small because Singapore sits close to the central meridian of the UTC+8 time zone. But for practitioners in Australia, the United States, or any large country with a single time zone, the gap between solar time and clock time can be large enough to completely change the chart.

Understanding True Solar Time

True solar time is based on the actual position of the sun at your specific longitude. The sun crosses your local meridian at true solar noon, when it reaches its highest point in the sky. This happens at a different moment for every longitude, even within the same time zone.

True solar time differs from mean solar time by a small amount called the equation of time. The equation of time varies throughout the year because the earth’s orbit is elliptical and its axis is tilted. The difference ranges from about negative fourteen minutes to positive sixteen minutes depending on the date. For most practical QMDJ purposes, the equation of time is a second-order correction, but if you want maximum precision, you should include it.

The formula for true solar time is: true solar time equals clock time plus the longitude correction plus the equation of time. The longitude correction is the difference between your longitude and the standard meridian of your time zone, multiplied by four minutes per degree. The standard meridian for UTC+8 is 120 degrees east. For UTC+5 (US Eastern, EST), it is 75 degrees west.

You can learn about the broader stems and branches system that underlies this time conversion, because the twelve earthly branches that define the Chinese hours are the same branches used in all of Chinese metaphysics.

The Twelve Hour Branches

The Chinese day is divided into twelve two-hour blocks, each governed by one of the twelve earthly branches. These branches are the same twelve symbols used in the sexagenary cycle for years, months, and days. Here is the complete mapping:

Branch	Chinese Name	Time Block	Animal
Zi	子	23:00 to 00:59	Rat
Chou	丑	01:00 to 02:59	Ox
Yin	寅	03:00 to 04:59	Tiger
Mao	卯	05:00 to 06:59	Rabbit
Chen	辰	07:00 to 08:59	Dragon
Si	巳	09:00 to 10:59	Snake
Wu	午	11:00 to 12:59	Horse
Wei	未	13:00 to 14:59	Goat
Shen	申	15:00 to 16:59	Monkey
You	酉	17:00 to 18:59	Rooster
Xu	戌	19:00 to 20:59	Dog
Hai	亥	21:00 to 22:59	Pig

Note that the Zi hour begins at 11pm, not at midnight. This is a common source of confusion. The Chinese day begins at the Zi hour, which means a date change occurs at 11pm, not at midnight. If you are plotting a chart for 11:30pm on January 15, the Chinese date for divination purposes is January 16, not January 15.

This night-boundary rule is one of the most common plotting errors. If you get the date wrong, the day stem and day branch will be incorrect, which means the entire chart will be built on a false foundation. Always check: does your reading time fall before or after 11pm? If it falls after 11pm, advance the date by one day before calculating the day pillar.

Step 1: Convert Clock Time to True Solar Time

The first step in plotting is converting your local clock time to true solar time. Here is the procedure:

Find your longitude. You can use any GPS app or online mapping tool. For example, Singapore is at approximately 103.8 degrees east. New York City is at approximately 74 degrees west.

Find the standard meridian for your time zone. For UTC+8 (used in Singapore, Malaysia, Philippines, and others), the standard meridian is 120 degrees east. For UTC-5 (US Eastern Standard Time), the standard meridian is 75 degrees west. For UTC+0 (UK), it is 0 degrees (Greenwich).

Calculate the longitude correction. Take the difference between your longitude and the standard meridian, and multiply by four minutes per degree. If you are east of the standard meridian, add time. If you are west, subtract. For example, Singapore at 103.8E is 16.2 degrees west of the 120E meridian, so the correction is approximately 65 minutes (subtract). Singapore clock time is about 65 minutes ahead of true solar time.

Apply the equation of time. Look up the equation of time value for your date. This changes the solar time by up to 16 minutes depending on the time of year. For practical purposes, many practitioners skip this step, but if you want precision, include it.

Adjust for daylight saving time if applicable. If your location observes DST and is currently in DST, subtract one hour from your clock time before applying the longitude correction.

The result is your true solar time. This is the time you use to determine the hour branch for the chart.

Step 2: Determine the Hour Branch

Once you have the true solar time, map it to one of the twelve branches using the table above. For example, a true solar time of 9:30am falls in the Si branch (09:00 to 10:59). A true solar time of 1:15pm falls in the Wei branch (13:00 to 14:59).

Edge cases require care. If your true solar time is exactly on a boundary (for example, 11:00am sharp), you need to decide which branch to use. By convention, the boundary belongs to the later branch. So 11:00am belongs to the Wu hour (11:00 to 12:59), not the Si hour. However, in practice, many practitioners add a one-minute buffer: they wait until 11:01 before using the new branch. This avoids ambiguity and acknowledges the precision limits of solar time calculation.

If your true solar time falls in the Zi hour (23:00 to 00:59), remember to advance the date by one day as discussed earlier. This is the only hour branch that spans midnight, and the date change rule applies specifically here.

Step 3: Determine the Day Pillar

The day pillar consists of a heavenly stem and an earthly branch. It changes daily and follows the sexagenary cycle. The sixty-pillar cycle repeats every sixty days, so if you know the pillar for any given date, you can calculate it for any other date by counting forward or backward.

The easiest way to determine the day pillar is to use a Chinese calendar or a QMDJ calculator that accounts for the true solar date. If you want to calculate it manually, you need a reference point: a known day pillar for a specific date, and then count forward by the number of days between that reference and your target date.

The day pillar gives you two critical pieces of information: the day stem (one of ten heavenly stems) and the day branch (one of twelve earthly branches). The day stem determines how the eight deities are placed across the palaces. The day branch, combined with the hour branch, determines how the stems are distributed across the chart.

Step 4: Build the Hour Pillar

The hour pillar also consists of a heavenly stem and an earthly branch. The hour branch is already determined from step 2. The hour stem is calculated from the day stem and the hour branch using the “five rat” rule (also called the “five zi” rule).

The five rat rule states that the heavenly stem of the Zi hour is determined by the day stem, and all subsequent hours follow in sequence from that starting point. Specifically:

If the day stem is Jia or Ji, the Zi hour stem is Jia.
If the day stem is Yi or Geng, the Zi hour stem is Bing.
If the day stem is Bing or Xin, the Zi hour stem is Wu.
If the day stem is Ding or Ren, the Zi hour stem is Geng.
If the day stem is Wu or Gui, the Zi hour stem is Ren.

Once you know the Zi hour stem, count forward through the ten stems (Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui) as the hours advance through the twelve branches. For example, if the day stem is Jia and you are reading the Si hour (sixth hour from Zi), the Zi hour stem is Jia, the Chou hour stem is Yi, the Yin hour stem is Bing, the Mao hour stem is Ding, the Chen hour stem is Wu, and the Si hour stem is Ji.

The hour pillar gives you the hour stem, which is the most important single variable in the hour chart. The hour stem becomes the ruling stem, and the palace containing it becomes the ruling palace.

You can learn more about the ten stems in QMDJ to understand how stem relationships shape the entire chart reading.

Step 5: Place the Ruling Stem in the Ruling Palace

The hour stem determines the ruling palace through a fixed mapping. Each of the ten heavenly stems corresponds to a specific palace based on the Luoshu number associated with that stem’s element and the stem’s yin-yang polarity. The mapping is as follows:

Hour Stem	Palace Number	Direction
Jia (yang wood)	3	East
Yi (yin wood)	4	Southeast
Bing (yang fire)	9	South
Ding (yin fire)	2	Southwest
Wu (yang earth)	2 or 5 (varies by school)	Southwest or Center
Ji (yin earth)	2 or 8 (varies by school)	Southwest or Northeast
Geng (yang metal)	7	West
Xin (yin metal)	6	Northwest
Ren (yang water)	1	North
Gui (yin water)	1 (same as Ren, or 1/8 by school)	North

Some variations exist between QMDJ schools regarding the placement of Wu and Ji stems. The most common convention assigns Wu to the center palace and Ji to the southwest (2) or northeast (8). Always check which convention your calculator or software follows and be consistent.

Once the ruling stem is placed in the ruling palace, that palace becomes the focal point of the chart. The other stems are distributed to the remaining palaces following the ten-stem rotation cycle. Each stem rotates to its next position, creating a chain that fills the palaces in a specific order.

Step 6: Place the Eight Doors

The eight doors are placed based on the hour branch and the day’s solar term. The process begins with identifying the current solar term, which determines the starting position of the door cycle. The doors then rotate through the palaces following a specific sequence.

The eight doors are: the Open Door (Kai), the Rest Door (Xiu), the Life Door (Sheng), the Harm Door (Shang), the Obstacle Door (Du), the Death Door (Jing), the Fear Door (Jing), and the Arrest Door (Jing). Each door carries a specific quality that modifies the energy of the palace it occupies.

The door rotation follows the Luoshu number sequence, adjusted for the solar term. In practice, the exact door placement formula varies between QMDJ schools, but all follow the same principle: the door cycle starts at a specific palace determined by the season and advances by one position per hour branch.

When the door placement is complete, each of the eight occupied palaces has a door. The center palace (5) typically receives no door in standard QMDJ hour chart plotting. However, some schools assign a ninth door or treat the center as a special case.

Step 7: Place the Nine Stars

The nine stars are placed based on the hour stem and the day stem. The star rotation follows a pattern tied to the Luoshu numbers and the five elements. Each star carries a specific quality:

Tian Peng (Heavenly Pig): associated with water, danger, and bold action. Tian Rui (Heavenly Profit): associated with earth, illness, and obstacles. Tian Chong (Heavenly Charge): associated with wood, sudden movement, and military energy. Tian Fu (Heavenly Helper): associated with wood, benevolence, and protection. Tian Qin (Heavenly Bird): associated with earth, harmony, and mediation. Tian Xin (Heavenly Heart): associated with metal, healing, and authority. Tian Zhu (Heavenly Pillar): associated with metal, support, and stability. Tian Ren (Heavenly Man): associated with water, wisdom, and adaptability. Tian Ying (Heavenly English): associated with fire, brilliance, and visibility.

The star placement starts from the ruling palace and follows the Luoshu sequence. The exact formula varies by school, but the principle is always the same: the ruling palace receives a specific star based on the hour stem, and the remaining stars fill the other palaces in a set order.

You can learn more about the nine stars in QMDJ to understand how each star modifies the palace it occupies.

Step 8: Place the Eight Deities

The eight deities (also called spirits or gods) are placed based on the day stem. The deity rotation follows a fixed pattern that depends on whether the day stem is yang or yin. The eight deities are:

Zhi Fu (Value Symbol): the ruling deity, placed in the same palace as the ruling stem. She She (Snake): associated with deception, confusion, and hidden schemes. Tai Yin (Great Yin): associated with concealment, secrets, and female energy. Liu He (Partner): associated with cooperation, marriage, and partnership. Bai Hu (White Tiger): associated with danger, injury, and aggressive action. Xuan Wu (Black Tortoise): associated with wisdom, sexuality, and hidden things. Jiu Di (Nine Earth): associated with nurture, caution, and defensive energy. Jiu Tian (Nine Heaven): associated with authority, ambition, and high aspirations.

The deity placement starts from the ruling palace (where Zhi Fu always sits) and follows one of two sequences depending on whether the day stem is yang or yin. For yang day stems, the deities follow a clockwise rotation through the palaces. For yin day stems, they follow a counterclockwise rotation. This dual rotation pattern ensures that the deity placement shifts appropriately depending on the polarity of the day.

The eight deities in QMDJ each modify the reading of the palace they occupy, adding a layer of hidden influence to the visible door and star readings.

Step 9: Place the Earthly Branches in the Palaces

Each palace also receives an earthly branch based on the hour. The branch placement follows the Luoshu sequence, mapping to the directional positions. The branch in each palace interacts with the stem in that palace through the standard combinations and clashes of the earthly branch system.

The key combinations to check include: the six combinations (Zi-Chou, Yin-Hai, Mao-Xu, Chen-You, Si-Shen, Wu-Wei), the three harmonies (Shen-Zi-Chen water, Hai-Mao-Wei wood, Yin-Wu-Xu fire, Si-You-Chou metal), and the six clashes (Zi-Wu, Chou-Wei, Yin-Shen, Mao-You, Chen-Xu, Si-Hai). When a palace’s branch combines with its stem, the palace energy is harmonized. When they clash, the palace energy is conflicted.

Step 10: Verify the Chart

After placing all the layers, your chart should have nine palaces, each containing a door (except possibly the center), a star, a deity ( except possibly the center), a heavenly stem, and an earthly branch. Here is a checklist for verification:

Check the ruling palace: does it contain the hour stem? If not, the stem placement is wrong. Check the date: if you are reading during the Zi hour after 11pm, did you advance the date? If not, the day stem and branch are wrong. Check the hour branch: does it match the true solar time? If not, the entire calculation was built on the wrong hour.

Check for duplicate placements: no two palaces should have the same door or the same deity (with the exception of certain advanced techniques). If you find duplicates, recheck the rotation pattern. Check the element balance: do the placed stems follow the correct production and control cycle relative to the palace elements?

Common Plotting Errors and How to Avoid Them

Even experienced practitioners make plotting errors. Here are the most common mistakes and how to avoid them:

Using clock time instead of solar time. This is the single most common error. Always convert to true solar time before determining the hour branch. The longitude correction is the most important step in the entire plotting process.

Forgetting the 11pm date change. The Zi hour starts at 11pm, and the Chinese date advances at that point. A chart for 11:30pm on Tuesday uses Wednesday’s day pillar, not Tuesday’s. This error is invisible if you do not check for it, because the chart will look plausible but be entirely wrong.

Using the wrong solar term. The door placement depends on the current solar term, and solar terms change on specific dates. If you use the wrong term, the doors will be one position off. Always verify the solar term for your date using a reliable Chinese calendar.

Mixing up yin and yang stem rotation for deities. The deity rotation direction depends on whether the day stem is yang or yin. Using the wrong direction places every deity in the wrong palace. Double-check the polarity of the day stem before applying the rotation.

Placing the hour stem in the wrong palace. The stem-to-palace mapping has variations for Wu and Ji. If your school uses a different convention than your software, the ruling palace will be wrong. Be consistent with one convention and document which one you use.

Using Software to Plot the Hour Chart

In modern practice, most practitioners use software to generate the hour chart automatically. The QMDJ calculator takes the date, time, and location, and produces a complete chart with all layers placed. This saves time and reduces the possibility of manual calculation errors.

However, software is not infallible. Different software packages may use different conventions for the Wu and Ji stem placement, the deity rotation, and the solar term boundaries. When you first use a new tool, verify it against a manual calculation for a known date. If the results match, you can trust the tool for future charts.

Always input the correct time zone and, if the software supports it, your longitude and latitude. Some calculators handle the solar time conversion automatically; others require you to input solar time directly. Read the documentation to understand which approach your tool uses.

The Relationship Between Solar Terms and Chart Construction

Solar terms (jie qi) are the twenty-four divisions of the Chinese solar year, each lasting about fifteen days. They mark specific points in the earth’s orbit around the sun and have been used in Chinese calendars for millennia. In QMDJ, the solar term determines the starting position of the door cycle, which means the term boundary is a critical plotting parameter.

The twenty-four solar terms begin with Li Chun (Start of Spring, around February 4) and proceed through the year. Each term changes the door cycle starting position, which shifts all door placements in the hour chart. Getting the term right is as important as getting the time right.

For plotting purposes, the solar term determines the “season palace” from which the door rotation begins. For example, during the Li Chun term (spring), the door cycle starts from the east palace (palace 3). During the Li Xia term (start of summer), it starts from the south palace (9). The rotation then advances through the Luoshu sequence from that starting point.

This seasonal rotation is the mechanism by which the chart reflects the time of year. Two charts cast at the same clock time but in different seasons will have different door placements, because the seasonal starting point shifted.

Manual Plotting Practice: A Worked Example

To illustrate the full plotting process, here is a worked example. Suppose you want to cast a chart for September 15, 2026, at 10:00am in Singapore.

Step 1: Convert to solar time. Singapore is at approximately 103.8E. The UTC+8 standard meridian is 120E. The longitude difference is 16.2 degrees, which equals about 65 minutes. True solar time is approximately 10:00am minus 65 minutes, or about 8:55am. Add the equation of time for September (approximately minus 5 minutes), giving roughly 8:50am true solar time.

Step 2: Determine the hour branch. 8:50am falls in the Chen hour (07:00 to 08:59). This is the fifth branch of the day.

Step 3: Determine the day pillar. Looking up September 15, 2026 in a Chinese calendar gives us the day pillar for that date. Let us say the day pillar is Geng Shen (yang metal Geng on the Shen branch).

Step 4: Build the hour pillar. The day stem is Geng. By the five rat rule, when the day stem is Geng, the Zi hour stem is Bing. Counting forward: Zi = Bing, Chou = Ding, Yin = Wu, Mao = Ji, Chen = Geng. So the Chen hour stem is Geng. The hour pillar is Geng Chen.

Step 5: Place the ruling stem. The hour stem is Geng (yang metal), which maps to palace 7 (west). The ruling palace is the west.

Step 6: Place the doors. The current solar term for September 15 is Bai Lu (White Dew), which started around September 7. Based on the solar term, the door starting position is determined, and the doors rotate from there to fill the palaces for the Chen hour.

Step 7: Place the stars. The hour stem is Geng. The star mapping starts from the ruling palace (west, palace 7) and the Heavenly Heart Star or another star is placed there based on the formula. The remaining stars fill the other palaces in the Luoshu sequence.

Step 8: Place the deities. The day stem is Geng (yang). Zhi Fu goes in the ruling palace (west). The remaining deities follow the yang rotation direction clockwise through the palaces.

Step 9: Place the earthly branches. The Chen branch is placed in the center palace (5) or the east palace (3) depending on the convention, and the other branches follow the sequence.

Step 10: Verify. Check that the ruling palace contains Geng, the date is correct (Zi hour boundary check is not needed since the time is 10am), the hour branch is Chen, and the solar term is Bai Lu.

Plotting on the Go: Practical Considerations

In real-world practice, you rarely have time to perform a full manual plotting calculation. Here are practical considerations for plotting charts in everyday situations:

Use a reliable calculator app. Find one that allows longitude input and handles the solar time conversion automatically. Test it against a manual calculation once, then trust it for regular use. Keep it on your phone so you can cast charts whenever a question arises.

Know your longitude correction. If you live in one place, memorize your longitude correction (the difference between your local solar time and clock time). This lets you mentally convert times on the fly and estimate which hour branch you are in without opening a calculator.

Be careful with the boundary hours. The Zi hour (11pm to 1am) is the most error-prone because it spans the date change. If you are casting a chart near 11pm, double-check the date. If you are casting near any hour boundary, take a moment to verify which branch you are in.

Account for travel. If you are travelling to a different longitude, your solar time correction changes. A chart cast in New York uses a different correction than one cast in London. Even within Singapore, the correction is consistent, but if you travel to Penang or Kuala Lumpur, the longitude changes slightly and the correction shifts by a few minutes.

The Five Elements in Time-Based Plotting

The five elements play a structural role in the plotting process. Each heavenly stem carries an element, and each palace has a fixed element. When you place the stems into the palaces, the elemental relationships between stem and palace tell you whether each palace is harmonious, conflicted, or neutral.

Wood stems (Jia, Yi) placed in wood palaces (3, 4) are in their home element: strong and comfortable. Wood stems placed in water palaces (1) receive nourishment: strengthened. Wood stems placed in metal palaces (6, 7) are under attack: weakened. Wood stems placed in fire palaces (9) feed the palace: the palace is strengthened but the stem’s energy is drained into production.

These elemental dynamics are built into the plotting process. You do not calculate them separately. Once the stems are placed in the palaces (step 5), the elemental interactions emerge automatically from the fixed palace elements. This is why the palace structure matters so much: it provides the elemental context that makes every stem placement meaningful.

How the Eight Trigrams Connect to the Plotting Process

The eight trigrams are mapped to the eight directional palaces, and their qualities influence how the plotted symbols interact with each palace. When you plot a chart and place the Open Door in the south (Li, fire) palace, the fire quality of the trigram modifies the meaning of the Open Door. Fire makes the openness visible, passionate, and attention-grabbing. If you place the same Open Door in the north (Kan, water) palace, water makes the openness deep, hidden, and emotionally resonant.

This trigram-level interaction is built into the grid structure and does not require a separate calculation step. The Luoshu arrangement ensures that each palace always carries its trigram quality, and any symbol placed in that palace automatically takes on that trigram’s flavor. This is why two charts with the same doors and stars but cast at different hours (when the doors are in different palaces) can tell completely different stories.

FAQ: Plotting the Hour Chart From Solar Time

Do I really need to use solar time, or is clock time close enough?

If you live near the standard meridian of your time zone, the difference might be small enough that the hour branch does not change. But if the difference is more than twenty minutes, you risk reading the wrong hour branch, which changes the entire chart. Always use solar time for accuracy.

What happens if my solar time falls exactly on an hour boundary?

By convention, the boundary belongs to the later branch. So 11:00am solar time belongs to the Wu hour (11:00 to 12:59), not the Si hour. In practice, many practitioners add a one-minute buffer to avoid ambiguity.

Does daylight saving time affect the chart?

Yes. If your location is currently observing DST, subtract one hour from your clock time before applying the longitude correction. DST is a social convention that does not change the position of the sun.

Which hour stem-to-palace mapping should I use for Wu and Ji?

The most common convention places Wu (yang earth) in the center palace and Ji (yin earth) in the southwest (palace 2). Some schools use palace 8 for Ji. Be consistent with one convention and ensure your calculator uses the same one.

How do I know which solar term I am in?

Look up the twenty-four solar terms for your date. Each term lasts about fifteen days. The term determines the door rotation starting position. Using the wrong solar term shifts all doors by one position.

Can I use a QMDJ calculator instead of manual plotting?

Yes, and most practitioners do. A good calculator handles the solar time conversion, stem and branch calculations, and symbol placement automatically. Verify it once against a manual calculation, then use it for regular readings. Always input your longitude for accurate solar time conversion.

Why does the Chinese date change at 11pm instead of midnight?

The Chinese day is divided into twelve two-hour blocks starting with the Zi hour at 11pm. The Zi hour is the first hour of the new day in the Chinese system, which is why the date advances at 11pm, not midnight. This is a fundamental convention of Chinese timekeeping that applies to all metaphysical systems, not just QMDJ.