Tian Xu: counted from Horse to the year branch

The start is Horse; count to the birth-year branch and stop

In plain words first: Tian Xu (天虚) is a minor star placed by the birth-year branch, and the method has two moves. Begin on the Horse palace and step forward through the branches until you arrive at the one that names the birth year.

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Landings come from the site engine (iztro 2.6.0, default settings) and agree with the counting in juan 2 of the Quan Shu; the third column lists the clash position of each year branch.

The placing verse for Tian Ku and Tian Xu sits in the second volume of the Zi Wei Dou Shu Quan Shu (紫微斗数全书) and has four lines. In plain words: both stars start from the Horse palace; on the Horse spot you call the year Rat; the two stars then go their separate ways; and you count to the birth-year branch, where the star settles. The words "Xu goes forward toward the Goat" are the ones for Tian Xu: in a Rat year it sits on Horse, and in an Ox year it moves forward one step to Goat.

In the picture one row stands for one year branch. The Rat year lands on Horse, the Ox year on Goat, and the count runs on until the Pig year lands on Snake, after which it returns to Horse and the cycle repeats every twelve years. The third column gives the answer to the next section in advance: it lists the branch opposite each year branch, and it matches the second column row by row.

The landing is the opposite of the year branch

Numbers make this clearer. Number the branches 0 to 11 from Rat to Pig, so Horse is 6. Tian Xu lands on 6 plus the number of the year branch; the branch opposite any branch is that branch plus 6. The two formulas are the same, so there is no need to memorize twelve rows: find the year branch, go to its clash position, and that is Tian Xu.

On a chart this reads: the palace holding Tian Xu is always the opposite palace of the palace sitting on the year branch. Checking against the engine: a person born at the Snake hour on 20 May 1990 (a Geng Wu year, 庚午) has the Life palace on Rat. The Horse year puts Tian Xu on Rat, so it enters the Life palace, and the Horse position holds the Travel palace, which is the Life palace's opposite. A second chart, born at the Dragon hour on 1 June 1998 (a Wu Yin year, 戊寅), has the Life palace on Tiger; the Tiger year puts Tian Xu on Monkey, which is the Travel palace, and the year branch Tiger carries the Life palace, so again the two are opposite.

Of the twelve places a Life palace can take, only one, the clash position of the year branch, brings Tian Xu into the Life palace.

Around New Year: which day the year branch changes

Tian Xu is placed from the year branch, so the year branch has to be settled first. The site's charts always change the year on the first day of the lunar year, with no switch. Inside the engine, minor stars take their year branch from the "horoscope boundary" setting, which is also fixed on that day. When a chart from software that changes the year at the Start of Spring (立春) is set beside it, anyone born between the Start of Spring and the lunar new year sees Tian Xu one step apart.

Take 2024. On 9 February, the last day of the twelfth lunar month, the year branch is still the Rabbit of Gui Mao (癸卯) and Tian Xu is on Rooster. On 10 February, the first day of the lunar year, the year is Jia Chen (甲辰) and Tian Xu is on Dog. If the year changes at the Start of Spring instead, someone born on 6 February, after the 4 February start of spring but before the lunar new year, has Tian Xu moved from Rooster to Dog.

When comparing with another chart, keep two things apart: the printed year pillar follows the "year boundary", while minor stars take their year branch from the "horoscope boundary", and the engine sets the two separately. Software that moves only the second one to the Start of Spring can print Gui Mao as the year pillar while Tian Xu is already placed from Jia Chen, on Dog. For the rules on year changes, leap months and day boundaries, see leap months, birth hour and day boundary settings.

The same landing, a different palace when the Life palace moves

Which branch Tian Xu lands on depends only on the year branch. Which palace it enters also depends on where the Life palace sits, and that is set by the birth month and hour. Take a Rat-year birth, where Tian Xu is fixed on Horse. The four charts below differ only in the Life palace:

The book has a separate question-and-answer entry for Tian Ku and Tian Xu (juan 1). Besides cases by palace name, such as the Life and Parents palaces, it singles out three branch positions: Ox, Rabbit and Monkey. To see which birth years put Tian Xu on those three, work backward from the clash rule:

Where the book files it, and how far this page reads

Juan 1 opens its question on the two stars with a classification:

Ku and Xu are malefic stars.

It then lists cases by palace name, by the stars sharing the palace and by the "two limits" (the decade limit and the minor limit). That is the book's own system, with its own conditions and verdicts. The site's chart page marks Tian Xu as a piece of positional information; what lies beyond position is left to the reader to check against the specific passage.

1. 1

   Settle the year branch

   For births around Chinese New Year, confirm whether the chart changes the year on the first lunar day or at the Start of Spring; the site uses the first lunar day.

2. 2

   Count to the clash position

   Start on Horse as Rat and count forward to the year branch, or go straight to the branch opposite it.

3. 3

   Then read the palace name

   Look at what that branch is called on your chart, and check that it is the opposite of the palace holding the year branch.

To follow the star that walks the other way in the same verse, read Tian Ku; for how minor stars sit among the main and helper stars, see auxiliary, malefic and minor stars; positional relations such as "the opposite palace" are covered in opposite, flanking and converging palaces.