What is the Day Master in BaZi and how do you find yours

Where the Day Master sits in a chart

A BaZi chart, also called the Four Pillars of Destiny, is built from two sets of signs: ten Heavenly Stems, from Jia to Gui, and twelve Earthly Branches, from Zi to Hai. The Hong Kong Observatory explains that paired in order they make a cycle of sixty starting with Jia-Zi, that such pairs have named years and days for two to three thousand years, and that the pairs for the year, month, day and hour together form the Eight Characters, ba zi in Chinese.

Each pillar is one pair: a stem on top and a branch below. The Day Master is the top character of the day pillar. Everything else in the chart is described by how it relates to that one stem.

The classical texts say this plainly. Sanming Tonghui, a Ming-dynasty compendium attributed to Wan Minying, gives the year as the root, the month as the sprout, the day as the flower and the hour as the fruit, and calls the day the master and one's own self. It also records the shift that made the day central: the old method read a person from the year, while the Ziping school reads from the day. The Ming-era text Yuanhai Ziping puts it the same way in its section On Taking the Day as Master: take the day stem as the master.

The ten Day Masters

Because the Day Master is a Heavenly Stem, there are exactly ten possible Day Masters. Sanming Tonghui describes the ten stems as five yang and five yin, the yang being firm and the yin soft. In order, Jia is yang wood and Yi yin wood, Bing yang fire and Ding yin fire, Wu yang earth and Ji yin earth, Geng yang metal and Xin yin metal, Ren yang water and Gui yin water.

The same chapter gives each stem a picture in the sky and on the earth. Jia is thunder and the dragon above, beams and pillars below; Yi is wind above and trees below. Bing is the sun and lightning, and on earth the furnace; Ding is the stars, and on earth the lamp. Wu is mist above and mountains below, while Ji is described as the true soil of the earth. Geng is wind and frost above, metal and iron below; Xin is linked with the sun and moon and, on earth, with metal in the ore of mountain rock. Ren is clouds and marshes, and Gui is rain and dew above and springs below.

These images describe the character of each stem. They are descriptions, not ranks.

How to find your Day Master

Your Day Master depends only on the day pillar. Li Chun and the solar terms, which decide the year and month pillars, play no part; what matters is which day you were born on, counted the way the chart counts days.

1. Write down your birth date, clock time and place, and check whether daylight saving time was in effect. The National Institute of Standards and Technology describes it as the period when clocks are moved one hour ahead; in the United States the rules in place since 2007 run from the second Sunday of March to the first Sunday of November, and earlier years followed different dates.
2. Check the hour. In the Observatory's table the Zi double-hour runs from 23:00 to 01:00, so it straddles midnight. A birth between 11 pm and midnight is in the Zi hour but still on the earlier calendar date, and a calculator has to choose whether to give it that day's pillar or the next day's. Find out which rule yours uses.
3. Look up the day's stem-branch pair in a calendar table, or let a calculator do it. The stem of that pair is your Day Master. Steps 1 and 2 only matter for births close to midnight.

Reading the chart from the Day Master: the Ten Gods

Once the Day Master is fixed, every other stem in the chart gets a name based on its element and its yin or yang relative to the Day Master. Yuanhai Ziping sets these out with Jia as the example. Jia meeting Jia is the Companion and meeting Yi is Rob Wealth. Bing is the Eating God and Ding the Hurting Officer. Wu is Indirect Wealth and Ji Direct Wealth. Geng is the Seven Killings, also called the Indirect Officer, and Xin the Direct Officer. Ren is the Indirect Resource and Gui the Direct Resource.

The pattern behind the list is the element cycle. The text groups the relationships into five pairs: the element that controls the Day Master gives the officers, the element the Day Master controls gives wealth, the element that produces it gives resource, the element it produces gives the eating and hurting stars, and its own element gives stems of its own kind, Rob Wealth among them. Within each pair, the same polarity and the opposite polarity get different names. This is why the same stem can be wealth in one person's chart and an officer in another's: the names only exist relative to a Day Master.

Common mistakes when looking up a Day Master

Confusing it with the zodiac animal. The animal people quote as their Chinese sign belongs to the Earthly Branch of the year. Sanming Tonghui notes that the branches carry animals, from the rat for Zi to the pig for Hai, while the stems do not. Your Day Master is a stem from a different pillar, so it has no animal at all.

Taking a summer clock time at face value. Near midnight, an uncorrected daylight saving hour can move you to the neighboring day and change the Day Master. Convert to standard time first, using the rules for the year and place you were born.

Ignoring how far the time zone is from the sun. NOAA's solar calculation sets the offset between clock time and true solar time as the equation of time plus four minutes for every degree of longitude, minus the time zone's hours. A place 15 degrees west of its zone's meridian therefore runs about an hour behind the clock. So a calculator that converts to true solar time can put a late-evening birth on a different day from one that does not, so check which kind you are using.

Treating the Day Master as the whole reading. Yuanhai Ziping says that with the day as master, a reader still looks at whether the self is strong or weak, at the month, at the balance of the five elements and at the timing of luck. DayMaster, a BaZi calculator for the phone, shows your Day Master on a card with the four pillars, Ten Gods and element count right below it. To fix the day, it asks for the city of your birthplace time zone, converts daylight saving time back to standard time and counts a birth from 11 pm as the next day's Zi hour.

This guide explains how the BaZi tradition defines and calculates the Day Master. It is offered for reflection and entertainment and is not a prediction or advice of any kind.

Frequently asked questions