Month Pillar — 月柱 yuè zhù

The calculator shows which solar term opened your month and how many days you were born after it.

Open the free BaZi calculator or the related tool to see Month Pillar applied to a real birth chart.

A BaZi chart is a small, fixed data structure: four pillars, each a heavenly stem above an earthly branch, with one to three hidden stems inside every branch. Everything else — Ten Gods, element counts, strength, luck pillars — is computed from those eight characters plus the birth moment and the gender option used for luck direction.

Because the structure is fixed, the most important practical question is whether each pillar was calculated correctly. The year depends on the exact 立春 instant, the month on the twelve 节 solar terms, the day on an unbroken sixty-day count and the hour on solar time. A single wrong pillar changes the Day Master or the month command and therefore every conclusion built on top.

Positions also carry meaning. Traditional texts read the year as roots and early years, the month as parents and social environment, the day as self and spouse and the hour as children and later life. These associations are heuristics for where to look, not separate predictions.

• Using the lunar New Year instead of 立春 for the year pillar.
• Using lunar months instead of solar-term months.
• Ignoring historical time zones and daylight saving.
• Reading a single pillar without the rest of the chart.

The four-pillar method is usually traced to the Song-dynasty 渊海子平, which made the day stem the centre of the chart. Later works such as 三命通会 (Ming) collected and systematised the rules used today.

• Seasonal StrengthSeasonal strength rates each element by the month: the element of the season is prosperous (旺), the one it generates is strengthening (相), the one that generated it rests (休), the one controlling it is confined (囚) and the one it controls is dead (死).
• Solar TermsThe twenty-four solar terms divide the sun's path into 15° steps.
• Four PillarsThe Four Pillars are the year, month, day and hour of birth, each written as a heavenly stem over an earthly branch.
• Year PillarThe year pillar is the stem-branch pair of the solar year of birth.
• Day PillarThe day pillar is the stem-branch of the birth day in the continuous sixty-day cycle, which has run unbroken for well over two thousand years.
• Hour PillarThe hour pillar covers one of twelve two-hour periods (时辰), starting with 子 at 23:00–01:00.

The fastest way to understand Month Pillar is to look at real charts rather than memorise rules. Enter a birth date, time and city in the BaZi Calculator, then locate where Month Pillar appears: in a visible stem, hidden inside a branch, in the current luck pillar or in this year's annual pillar. Note the position, because the year pillar is usually read as background and early life, the month pillar as environment and career setting, the day pillar as the self and close partner, and the hour pillar as later life and output.

• Compare two or three charts where Month Pillar is prominent and two where it is absent; write down what differs in the overall balance.
• Check the month branch first: seasonal strength changes how much any factor matters.
• Use the hidden-stems and Ten Gods tables in the calculator output instead of guessing.
• Treat single factors as clues, never as verdicts; classical texts always weigh the whole chart.

Different schools describe Month Pillar with slightly different emphasis. This site follows widely used conventions (solar-term months, true solar time optional, Zi hour setting configurable) and states them openly so you can compare results with a book or another calculator.

Month Pillar is one piece of a larger system. If you are learning BaZi from scratch, the order below builds each idea on the previous one, and every step links to free reference pages on this site.

1. Calculate a chart and confirm the four pillars are correct (checklist).
2. Learn the ten heavenly stems and twelve earthly branches.
3. Find your Day Master and judge its strength with the five elements.
4. Read the Ten Gods in context.
5. Move on to timing with luck and annual pillars.
6. Use the glossary whenever a term is unfamiliar.

BaZi is a traditional cultural system. This page explains how the symbols are defined and read; it does not make scientific claims or predictions about your health, money or relationships.