Day Master

Meaning

The Day Master is the Heavenly Stem of the day pillar: of the eight characters of a birth, the one BaZi reads as the self. Its name, 日主 rìzhǔ, is “the master of the day”; the books also call it 日元 rìyuán, “the day’s origin”, and 日干 rìgān, simply “the day’s stem”. Everything else in the chart is read from where it stands: each other stem, shown or hidden in a branch, is one of the Ten Gods by how its phase meets the Day Master’s, and whether their polarities agree.

Each of the ten stems makes a different self, and the tradition gives each an image from nature, after the Di Tian Sui’s verses: Jia the tall tree, Yi the vine and the flower, Bing the sun, Ding the candle and the lamp, Wu the mountain, Ji the field, Geng the ore and the axe, Xin the jewel, Ren the river and the sea, Gui the rain and the dew. Ulune’s reading of the Day Master gives that image, and then reads the rest of the chart as its landscape: the season it was born in, what supports it, what it feeds, what shapes it.

No Day Master is better than another. A tree in spring and a tree in winter are the same tree in different weather, and the classics read a chart by how its self and its surroundings meet rather than by the self alone. The Day Master says who is standing in the landscape; the other seven characters say what the landscape is like.

In practice

• On the board, the day’s stem is outlined and marked Day Master rather than with a god; its reading gives the stem’s image and the tradition’s view of the self.
• The Ten Gods: every other stem is named from it. For a Jia Day Master, Bing is the Eating God, Geng Seven Killings, Gui the Direct Resource; for a Geng Day Master, the same Jia is Indirect Wealth.
• The analysis: the balance of the phases, the Day Master’s strength, the structure and the favourable phases are all measured from it.
• Two people: the Relationship lens compares the two Day Masters, what each is to the other among the Ten Gods, and whether the two stems combine or clash.
• In time: every luck pillar, year, month and day is named by its stem’s god for the Day Master.
• Without a birth time, the Day Master is still known: only a birth near the day’s turn, 23:00 by Ulune’s default, leaves it uncertain.

Across traditions

• In Japan, Korea and Vietnam it is the nikkan, the day stem, of Shichū Suimei, the ilgan of saju and the nhật chủ of Vietnamese Tứ Trụ, the self in each.
• In Western astrology the Sun plays the nearest part, the self a chart turns around; but where the Sun is read by its sign, the Day Master is read by its phase within a landscape of seven other characters.
• In popular books, “What element are you?” usually means the Day Master’s phase and polarity: a Yang Fire person is a Bing Day Master, not someone born in a Fire year.

Origin and history

The day stem was not always the self. Li Xuzhong, under the Tang, read a life from the year, month and day of birth, with the year at the centre, as Han Yu’s epitaph for him records in the early 9th century. Xu Ziping, in the 10th century, moved the centre to the day’s stem and added the hour, and the school that bears his name has read the Day Master as the self ever since. The Song dynasty Yuanhai Ziping set out the method; the Di Tian Sui gave each stem its verse, which Ren Tieqiao’s commentary of the Qing dynasty unfolds; and Shen Xiaozhan’s Ziping Zhenquan, in the 18th century, built its structures on the Day Master and its month.

How Ulune calculates it

The Day Master is the stem of the day pillar. Ulune reads the day on the birthplace’s own clock, true solar time by default, local mean time or the civil clock on request, and turns it at 23:00, the start of the Rat hour, as the Zi Ping school counts, with midnight and the split Rat hour as options. The day’s place in the sixty-cycle is its Julian day number plus 49, modulo 60, and its stem is that place modulo 10. Every other stem’s god follows from the two phases, the same, producing, controlled, controlling or producing it, and from whether the two polarities agree; a birth within five minutes of the day’s turn is marked uncertain.

Correspondences