Month pillar

Meaning

The month pillar, 月柱 yuèzhù, is the second of the four pillars: the stem and branch of the solar month of birth, which runs from one of the twelve opening terms to the next. Its branch is fixed by the season, the Tiger month from Lichun, the start of spring, the Rabbit month from Jingzhe, and so round to the Ox month from Xiaohan in January; its stem follows from the year’s.

The classics call the month branch the month’s command, 月令 yuèlìng: the season the self was born into, and the strongest of the four branches. A Wood Day Master born in spring stands in its own season; the same stem born in autumn meets the season of the Metal that cuts it. That is why the month weighs most in everything Ulune measures: the balance of the phases, the Day Master’s strength, the structure, the climate the chart asks for, and the luck pillars, which all start from it.

The tradition also gives the month a circle of people and a time: the parents and the home one grows up in, the brothers and sisters, the years of youth. Ulune keeps the month’s sense of season and setting, and does not read ages from the pillars.

In practice

• The season: the month’s hidden stems count twice in the balance of the phases, and the first test of strength asks whether the month’s main qi is the Day Master’s own phase or the one producing it.
• The structure: the chart’s frame is named from the month branch, from its hidden stem that shows among the stems or from its main qi.
• The climate: the winter months, Hai, Zi and Chou, ask for Fire’s warmth; the summer months, Si, Wu and Wei, for Water’s moisture.
• The luck pillars run from the month pillar, one step of the sixty-cycle per ten years, forward or backward.
• Stars read from it: Heavenly Virtue and Monthly Virtue are found from the month branch.
• A turning month: the month turns at the exact instant of its opening term, so no clock or time zone can move it; a birth within five minutes of a term is marked uncertain.

Across traditions

• In Japan and Korea it is the getchū of Shichū Suimei and the wolju of saju.
• In Western astrology the nearest idea is the Sun’s sign, which is also a season: the solar months begin when the Sun reaches the middle of a sign, 15° of Aquarius for the Tiger month, so a Chinese solar month straddles two Sun signs.
• In Chinese astrology the month’s branch is the month animal, the inner animal.

Origin and history

The months took their branches from the sky. The Huainanzi, in 139 BC, describes the handle of the Dipper pointing to a new direction each month, to Yin in the first month of spring, and the month “established” in that branch gave its name; the solar terms fixed the months to the Sun. The Song dynasty Yuanhai Ziping and the San Ming Tong Hui read the month as the season of the self, and Shen Xiaozhan’s Ziping Zhenquan, in the 18th century, made it the key to the chart: the use, it teaches, is to be sought in the month alone. Xu Lewu’s commentary of 1936 carried that rule into modern teaching.

How Ulune calculates it

Ulune finds the solar month of a birth between two opening terms, the Sun at 315° for Lichun and every 30° after, as instants. The branch is Yin in the month from Lichun and follows the twelve in order. The stem follows the year’s by the classical rule of the five tigers, the same as counting months unbroken through the sixty-cycle, twelve a year, from Bing-Yin in the Tiger month of 1984. A birth within five minutes of a term is marked uncertain.

Correspondences