Zuo Fu: month one sits at the Dragon position

Month one at the Dragon position, then one step per month

In plain words first: Zuo Fu (左辅) is placed by the lunar month of birth. Month one goes on the Dragon (辰) position, and every later month moves one branch further along.

Open the full-size diagram

Placement sketch: the twelve branches in the usual Rat, Ox, Tiger order around a circle, not the real chart layout. Month numbers follow the Quan Shu rule and were checked month by month against the engine.

Each circle in the picture reads branch plus month: Dragon 1, Snake 2, Horse 3, and on to Rabbit 12. Twelve months make one lap of the circle, no branch holds two months and none is left empty. A person gets exactly one Zuo Fu, and the only input that decides it is the lunar month.

The classic compendium Zi Wei Dou Shu Quan Shu (紫微斗数全书) puts this rule in its second juan, in the song for placing Zuo Fu and You Bi:

Zuo Fu starts from the Dragon with the first month and goes forward. Whoever is born in the first month, put it in the Dragon palace; the second month is in the Snake palace.

"Forward" means in the order of Rat, Ox, Tiger, Rabbit. The opening line of the same song is shorter still: Zuo Fu starts in the first month at the Dragon. Find "Dra 1" in the picture and that is the starting point.

The same month can land in differently named palaces

The month fixes the branch, not the palace name. The twelve palace names are counted from the Life palace, so whichever branch the Life palace falls on decides what number, and which name, Zuo Fu's branch gets.

Take one concrete month. April 18, 2024 is lunar month three, day ten, and Zuo Fu always sits on Horse. Change only the birth hour and the Life palace moves, so the same Horse palace gets another name:

So Zuo Fu is written down in two lines. The first, "lunar month to branch", depends on the month alone. The second, "which palace is that branch", can only be filled in once the Life palace is placed. What each of the twelve palaces discusses is in the twelve Zi Wei palaces.

Leap months: the second half counts as the next month

In a year with a leap month, which month do you count for someone born inside it? The site default, "split the leap month", is: days one to fifteen of the leap month count as that month, and from day sixteen they count as the next month.

The year 2023 has a leap second month, running from March 22 to April 19. Take someone born in the Dragon hour. On leap month two, day 15 (April 5) Zuo Fu is on Snake, the second-month position. On leap month two, day 16 (April 6) it jumps to Horse, the third-month position, and April 20, the first day of month three, is still Horse.

A related sentence closes the Quan Shu's rules for placing the Life and Body palaces: for someone born in a leap first month, start counting from the second month, and every leap month follows that example. Read literally, that moves the whole leap month onto the next month and says nothing about a day-fifteen cutoff. Neither engine setting, "split" or "whole month counts as this month", matches that literal reading, so a note should say which one it used.

When the month flips, more than Zuo Fu moves: for the same Dragon-hour birth the Life palace changes from Pig to Rat. The settings also offer a "whole leap month counts as that month" option, and with it April 8 keeps Zuo Fu on Snake. Why this one cutoff reshapes a whole chart is covered in leap months, hours and the day boundary.

Counting Santai from Zuo Fu

Once Zuo Fu has a place, other stars borrow it as the start of a day count. The Quan Shu's song for placing Santai and Ba Zuo says:

For Santai, look for Zuo Fu: put the first day on the Zuo Fu palace and count forward to the day of birth.

In other words, put lunar day one in the Zuo Fu palace, move one palace forward for each following day, and the palace where you stop on the birth day is Santai.

The second row shows the pattern: day 13 is exactly twelve days after day 1, so Santai wraps back onto the Zuo Fu palace. How Santai itself is placed and read has its own article, Santai.

Where the book files Zuo Fu

A section of juan 2 sorts the stars between the Northern and Southern Dipper and among the five elements. It lists the fourteen main stars, then Wen Chang and Wen Qu, and notes that Zuo Fu and You Bi belong to the Northern Dipper. Then it closes the list with a boundary:

Everything above, from Zi Wei to the two assistants, eighteen stars in all, are the proper stars of the Northern and Southern Dippers; Kui, Yue and Tian Ma are also auspicious stars but are not counted among the proper stars.

Count them: fourteen main stars, plus Wen Chang and Wen Qu, plus Zuo Fu and You Bi, makes eighteen. The book's "proper stars" end at the two assistants, and Tian Kui, Tian Yue and Tian Ma sit outside that group. The site groups them all as supporting stars, but this boundary comes from the book, not the product.

Two cross-checks, both on what Zuo Fu lacks. The brightness table in the Quan Shu has twelve rows and Zuo Fu is in none of them, and the engine gives it no grade. In the transformation table it appears once, as Ke in the year of Yang Water. In the Quan Shu's transformation song, the line for that stem puts Tian Fu, not Zuo Fu, in the Ke position, so the book and the engine's table differ here; the schools' choices are laid out in Hua Ke.

1. 1

   Write the lunar month first

   Convert the solar birthday; if the birth falls in a leap month, confirm whether the setting is "split" or "whole month".

2. 2

   Then count the branch

   Put month one on Dragon, count forward to the month, and write down the branch without naming the palace yet.

3. 3

   Name the palace last

   Once the Life palace is placed, count which palace that branch is, and only then look at the stars beside Zuo Fu.

To read the partner star next, go to You Bi, which counts the months in the opposite direction.