General concepts

Shichū Suimei (Japanese Four Pillars)

Also known as: shichu suimeishichū suimeishichusuimei四柱推命shichuu suimeijapanese four pillarsjapanese four pillars of destinyjapanese astrologyjapanese birth chartfour pillars japanshichu suimei calculatornikkan日干tsuhenseitsūhensei通変星jikkanjunishizokangogyotaiunrisshun立春bazisaju

Shichū Suimei (四柱推命), "reading destiny from four pillars", is the Japanese name and practice of the Four Pillars method, the same calculation as Chinese BaZi: the year, month, day and hour of birth each form a pillar of one stem and one branch, eight characters in all.

The name Shichū Suimei (四柱推命) means "reading destiny from four pillars". It is the Japanese name, and the Japanese practice, of the Four Pillars method that China calls BaZi. The calculation is the same one. The year pillar changes at Risshun (立春), the Japanese reading of Li Chun, the Start of Spring, around 4 February, and not at the lunar New Year. The months begin at the twelve Jie solar terms, the days run through an unbroken cycle of sixty, and the hour pillar covers a double hour of two clock hours. Each pillar is written with one stem and one branch, so a full chart has four pillars and eight characters.

What differs between countries is the vocabulary and the habits of reading. The ten Heavenly Stems are the jikkan (十干), and in Japanese each is read as a phase together with "elder" (e) or "younger" (to) brother: kinoe 甲, kinoto 乙, hinoe 丙, hinoto 丁, tsuchinoe 戊, tsuchinoto 己, kanoe 庚, kanoto 辛, mizunoe 壬 and mizunoto 癸. The twelve Earthly Branches are the jūnishi (十二支), and in Japan they are better known as the zodiac animals: ne, ushi, tora, u, tatsu, mi, uma, hitsuji, saru, tori, inu and i. The stem of the day pillar, the Day Master, is the nikkan (日干) and is the reference point of the whole chart. How every other stem relates to it gives the Ten Gods, the tsūhensei (通変星): hiken 比肩, gōzai 劫財, shokujin 食神, shōkan 傷官, henzai 偏財, seizai 正財, henkan 偏官, seikan 正官, hen'in 偏印 and inju 印綬. The stems hidden inside the branches are the zōkan (蔵干), and the five phases are the gogyō (五行).

Shichū Suimei is a symbolic system and a cultural tradition, not a science. What this entry describes is how the tradition reads a chart, never what will happen to anyone, and there is no evidence that eight characters fix a person's character or events.

One practical difference matters for the calculation: the clock. Japan Standard Time is reckoned from the meridian 135°E, which runs through Akashi. Tokyo lies near 139.7°E, so there the Sun is about 19 minutes ahead of the clock, while Fukuoka is about 18 minutes behind it. Whether to read the hour pillar from the official clock or from local solar time is therefore a real question, and the answer can change the hour pillar and, near midnight, even the day. AstroSensus offers local time as the option "Solar time at the birthplace", which uses the longitude of the birthplace and the equation of time, a correction that adds up to about 16 minutes more or less depending on the season. The default is the official clock time. Japan also had summer time in 1948–1951, and AstroSensus applies it automatically from the time-zone database, so you enter the clock time as it was on the day.

Japanese schools often add tables that AstroSensus does not show yet: the twelve stages, the jūni-un (十二運), other tables built on the Day Master and the branches, and the ten-year luck cycles, the taiun (大運). Schools disagree about their rules, and this entry does not describe them as settled.

The free Shichū Suimei calculator in AstroSensus uses the same engine as the BaZi calculator and shows the Japanese names beside the Chinese ones: the four pillars with their stems and branches, the Day Master, the hidden stems, the Ten Gods and the count of the five phases. It needs no account, uses no AI, and keeps the birth data only in the session.