Structure and Reading Order of a BaZi Chart

Basic Sections on a BaZi Chart

A standard BaZi chart is organized around four pillars, each representing a unit of time: year, month, day, and hour. Together these are known as the Si Zhu, or Four Pillars. Each pillar contains two characters: a Heavenly Stem above and an Earthly Branch below. This produces eight characters in total, which is where the term BaZi, literally “eight characters,” comes from.

The year pillar corresponds to the year of birth, expressed in the sexagenary cycle of ten Heavenly Stems and twelve Earthly Branches. The month pillar corresponds to the birth month, but it does not follow the lunar calendar. The day pillar represents the day of birth and is the anchor for the entire chart. The hour pillar corresponds to the two-hour period of birth, derived from the day stem and the birth time.

A basic chart may show only these eight characters. More detailed charts include additional sections such as hidden stems, the Ten Gods, Nayin, the twelve stages of life, and various symbolic stars. These are computed from the four pillars and their interactions. Understanding the basic structure is a prerequisite for reading any of these extended layers. Most readers begin with the day stem, known as the Day Master, because it represents the person. From there, the other pillars are read as influences on that core. A thorough introduction to these components appears in the BaZi basics guide.

Year and Month Pillars: How Solar Terms Define Boundaries

The year pillar and month pillar are both tied to the solar calendar, not the lunar calendar. In BaZi, the year begins at Li Chun, the beginning of spring, which typically falls on February 3, 4, or 5. A person born before Li Chun belongs to the previous year pillar, even if the lunar new year has already passed. This distinction is one of the first points of confusion for people coming from a lunar calendar background.

The month pillar is even more closely governed by solar terms. There are twelve month pillars, each corresponding to one “jie” or solar term boundary. These boundaries occur around the 4th to 8th of each solar month. For example, the first month pillar begins at Li Chun and ends at Jing Zhe. The second month pillar begins at Jing Zhe and ends at Qing Ming. This means the month pillar changes not on the first day of a lunar month, but at the precise moment of the relevant solar term. The concept is explained further in the Yue Ling glossary entry.

This has practical implications. Two people born in the same lunar month can have different month pillars if one is born before the solar term boundary and the other after it. Conversely, two people born in different lunar months can share the same month pillar if both fall within the same solar term interval. Because the month pillar sets the seasonal frame for the chart, this distinction affects how the strength of the Day Master is evaluated. The how to read BaZi chart article covers this in more depth.

Why the Day Pillar Is Independent of Solar Terms

The day pillar is computed differently from the year and month pillars. It does not depend on solar terms or the lunar calendar. Instead, it is produced by a continuous count of sixty-day cycles, where each day is assigned one of sixty possible stem-branch combinations. This sequence runs without interruption, year after year.

This continuous counting method has a long history and is still used in various traditional calendars. Because it does not reset at solar term boundaries or lunar month beginnings, the day pillar changes once per day, at a fixed point. The practical consequence is that the day pillar is stable and predictable. Two people born on the same calendar day, regardless of where they are in the year, will generally share the same day pillar.

This independence matters because the day stem is the Day Master, the central reference point for the chart. The Day Master’s relationship to the other stems and branches determines the Ten Gods. The day branch, meanwhile, contains hidden stems that are read as part of the person’s immediate environment. A discussion of the Day Master’s role and how its strength is assessed can be found in the day master strong vs weak article. The day pillar’s role in overall chart reading is also addressed in the free BaZi calculator explanation.

How the Hour Pillar Is Derived from Day Stem and Time

The hour pillar is not a fixed mapping from clock time to stem-branch. The Earthly Branch of the hour is determined by the two-hour slot of birth, known as a shichen. The Heavenly Stem of the hour is then derived from the day stem using a fixed pairing rule. This means the same clock time can produce different hour stems depending on the day stem.

There are twelve two-hour periods in a day. The first begins at 23:00 and ends at 00:59, corresponding to the Zi branch. The second runs from 01:00 to 02:59, corresponding to Chou, and so on. The branch is therefore easy to determine from the birth time. The stem requires the day stem as input. The starting point is the Zi hour stem, which is set by a rule based on the day stem. From there, the other eleven hour stems follow in sequence.

This derivation means the hour pillar carries information about both the time of day and the Day Master’s relationship to that time. In a full chart, the hour pillar is often read as representing later life, children, or outward expression. It is also used in some systems to assess the strength of the Day Master, because the hour branch is one of the four branches in the chart. For those using corrected birth times, the true solar time discussion is relevant, since the hour branch depends on the local solar time rather than standard clock time.

Additional Sections Computed by the Engine

Beyond the four pillars, a full chart typically includes several computed sections. The engine used on this site calculates the four pillars, the interactions between Heavenly Stems and Earthly Branches, hidden stems, the Ten Gods, Nayin, the twelve stages of life, symbolic stars, strength assessment, pattern perspective, and the luck pillar and annual, monthly, and daily cycles. It also handles lunar calendar conversion and true solar time correction.

Hidden stems, or Cang Gan, are stored within each Earthly Branch. They are read as latent influences that may emerge under certain conditions. The Ten Gods are derived from the relationship between each stem and the Day Master. They include positions such as Direct Wealth, Indirect Resource, and Seven Killings. These are not literal gods but relational categories.

Nayin assigns a symbolic element and imagery to each pillar. The twelve stages of life describe the phase of each stem within its branch. Symbolic stars are additional markers derived from specific combinations of stems and branches. The strength assessment and pattern perspective are interpretive layers used to evaluate the overall configuration. The luck pillar system extends the chart across time. These layers are described further in the BaZi luck pillars guide and the life report product page. The engine does not provide bone weight calculation, name recommendations, exam outcome prediction, or any deterministic event prediction.

Reading Order: What to Look at First and Later

A practical reading begins with the day stem. This is the Day Master, the reference point for everything else. The first question is not whether the chart is “good” or “bad,” but what the Day Master’s relationship is to the surrounding stems and branches. After identifying the Day Master, the next step is to look at the month branch. The month branch sets the seasonal frame and is the primary indicator of the Day Master’s strength.

From there, a reader typically examines the other stems and branches for their Ten God relationships to the Day Master. This shows which areas of life are emphasized in the chart. The hour pillar is often read next, as it represents the person’s outward expression and later life. The year pillar is then considered for broader generational and early-life influences.

After the four pillars themselves, the reader may look at hidden stems, symbolic stars, and the twelve stages. These add texture but should not override the basic structure. The yearly report shows how annual cycles interact with the natal chart. For a broader view of how charts are interpreted across different traditions, the Mangpai school article provides context. Finally, readers concerned with the reliability of chart interpretation may consult the what makes a BaZi page trustworthy discussion. The overall sequence is: Day Master first, month branch second, then the remaining pillars, then the extended layers.