How Are Tieu Han and Nguyet Han Placed, and How Do They Differ from Dai Han and Luu Nien?

How Do Tiểu Hạn, Nguyệt Hạn, Đại Hạn and Lưu Niên Differ?

Fortune cycles in Tử Vi (Vietnamese astrology) form a multi-layered system nested within one another, with each layer covering a different span of time. Đại hạn (also called đại vận) is the 10-year period that determines the "quality" of an entire stretch of life. Lưu niên, or tiểu vận, is the layer of a single year, showing the tone of that year. Nguyệt hạn, also called nguyệt vận, is the layer of one lunar month. Nhật hạn is the layer of a single day.

It is important to distinguish two easily confused terms: "tiểu hạn" and "lưu niên". In many texts, the two are used interchangeably to refer to the palace of the year. But in some interpretive systems, they are two different palaces on the same chart. Tiểu hạn is a palace fixed by nominal age, while lưu niên is usually tied to Lưu Thái Tuế, that is, the palace holding the wandering Thái Tuế star of the year being examined. Some call the palace counted from the base of the đại hạn "lưu đại hạn", not tiểu hạn. This is the clearest point of divergence between schools, and also where beginners most easily go wrong.

The general principle when reading: a smaller layer is always placed in the context of a larger one. A month that looks favorable but sits inside a challenging year must still be read with caution. Conversely, a slightly subdued month within a good year is usually just a temporary slowdown.

The Common Method of Placing Tiểu Hạn in the Texts

The method recorded in many Tử Vi Đẩu Số texts, such as the section on starting tiểu hạn in Đẩu số tinh thành, relies on the tam hợp (triad) group of the birth year branch. Each tam hợp group contains one character from the tứ kho (the four storehouses: Thìn, Tuất, Sửu, Mùi), and the starting palace for tiểu hạn is the palace opposite that storehouse character. Specifically: people born in the years Dần, Ngọ, Tuất start tiểu hạn at the Thìn palace; those born in the years Thân, Tý, Thìn start at the Tuất palace; those born in the years Hợi, Mão, Mùi start at the Sửu palace; those born in the years Tỵ, Dậu, Sửu start at the Mùi palace.

From that starting palace, we place nominal age 1. Then each year moves one palace, with males going forward and females going backward, regardless of whether that age is dương or âm. For example, a person born in the year Dần has Thìn as the starting palace. For a male chart: age 1 at Thìn, age 2 at Tỵ, age 3 at Ngọ, and so on forward around the earthly plate. For a female chart: age 1 at Thìn, age 2 at Mão, age 3 at Dần, age 4 at Sửu, and so on backward around the circle.

A notable point is that this rule does not distinguish male from female by the âm or dương of the birth year; it only distinguishes males going forward and females going backward. This differs from the method of placing đại hạn, which relies on the âm or dương of the birth year and gender to choose the direction of rotation.

How Is Nguyệt Hạn Placed?

Nguyệt hạn is the palace taken as the "mệnh of the month". To determine it, one must first have a base palace. The two most commonly cited starting methods are starting from the tiểu hạn palace of the year, or starting from the Lưu Thái Tuế palace of the year. From that base palace, we count backward according to the birth month, then count forward according to the birth hour to arrive at the nguyệt hạn palace. This method is recorded in Tử Vi kinh nghiệm quyển hạ, and it is also the approach used by the Nhật Nguyệt tool, specifically starting from the lưu Đẩu Quân of the year being examined.

The method of starting nguyệt hạn that the tool uses consists of these steps: take the lưu Thái Tuế palace of the year being examined as the first month, count backward to the birth month, then take the palace where you stop as the Tý hour and count forward to the birth hour. The palace reached there is the first month, and each subsequent month moves one palace forward. This method differs from starting nguyệt hạn from the tiểu hạn palace, and if one uses the method starting from the tiểu hạn palace, the monthly table will give different results.

Because the method involves both the birth month and the birth hour, each person's nguyệt hạn is different, even when they are examining the same calendar month. This is also why many people calculate the nguyệt hạn palace incorrectly right from the first step without realizing it, leading to a skewed reading for the whole month.

After placing the nguyệt hạn palace, one adds a group of monthly wandering stars to the chart. When these wandering stars land exactly on the nguyệt hạn palace, or coincide with strong stars already present on the original chart, the tone of the month is activated more clearly. That is why some months pass peacefully, while others visibly "have events".

How Is Nguyệt Hạn Calculated in a Leap Month?

According to Đẩu số tinh thành, a leap month is split in half. The first half of the leap month is counted according to the preceding month, and from the 16th onward it is counted according to the following month. The Nhật Nguyệt tool only returns the twelve regular months and does not separate out the leap month.

Three Layers of Đại Hạn, Lưu Niên and Tiểu Hạn on the Same Chart

To picture this, take an example chart. Suppose a person born in the year Nhâm Dần, belonging to Hỏa nhị Cục. According to the method of placing đại hạn based on the cục number and direction of rotation, the first đại hạn from age 2 to 11 sits at the Dần palace. The second đại hạn from age 12 to 21 sits at the Mão palace. The third đại hạn from age 22 to 31 sits at the Thìn palace.

For this same person, the tiểu hạn palace is placed according to the Dần Ngọ Tuất tam hợp group, starting at Thìn. If it is a male chart, nominal age 1 is at Thìn, 2 at Tỵ, 3 at Ngọ, and so on forward. If it is a female chart, nominal age 1 is at Thìn, 2 at Mão, 3 at Dần, and so on backward.

On the chart, these three layers may coincide, or may sit in three different palaces. When interpreting a year, one usually examines the đại hạn palace, the lưu niên palace and the tiểu hạn palace at the same time, then combines them with the Mệnh palace, the Thân palace and the tam hợp palaces such as Tài, Quan and Phúc. That is precisely why, in the same year, two people with different charts will get different results, even if they are the same age.

Why Do Schools Place Tiểu Hạn and Nguyệt Hạn Differently?

This is the clearest point of divergence in Tử Vi. Some schools start tiểu hạn from the Mệnh palace, rather than from the palace opposite the storehouse character. Some schools do not distinguish male from female, meaning both males and females go in the same direction. Some confuse tiểu hạn with lưu đại hạn, treating the palace counted from the base of the đại hạn as tiểu hạn. Some modern Chinese schools use Lưu Thái Tuế instead of tiểu hạn, that is, they take the palace holding the wandering Thái Tuế star as the palace of the year and no longer place tiểu hạn by nominal age.

With nguyệt hạn, the level of disagreement is even greater. There are many different ways of placing nguyệt hạn among the schools. Besides the two methods of starting from the Tiểu Vận palace and the Lưu Thái Tuế palace, there is also a method starting from the fixed Dần palace. Each method yields a different nguyệt hạn palace, and therefore a different interpretive result.

For this reason, when consulting texts, one should clearly identify which method that text uses, to avoid mixing several methods in a single reading. The Nhật Nguyệt site uses the method of placing tiểu hạn according to the tam hợp group of the birth year branch as presented above, that is, starting at the palace opposite the storehouse character, one age one palace, males forward and females backward regardless of âm or dương. For nguyệt hạn, the site uses the method of starting from the lưu Đẩu Quân of the year being examined as already stated. Readers need to know this in order to cross-check with other sources, and to avoid comparing results between two different systems and then concluding that one side is wrong.

What Should Be Kept in Mind When Reading Yearly and Monthly Cycles?

One, do not separate them from context. Nguyệt hạn must be placed within the yearly cycle, and the yearly cycle must be placed within the đại hạn. Ignoring the larger context and looking only at a single month or a single year easily leads to a skewed conclusion.

Two, pay attention to wandering stars coinciding in a palace. When the wandering stars of the month or of the year land on a palace that already holds strong stars on the original chart, that tone is activated more clearly. This is where visibly "eventful" months and years come from.

Three, keep the spirit of tendency. Yearly and monthly cycles show the inclination of that span of time, not a foretelling of something certain to happen. The purpose of reading is to prepare, to be more proactive, not to worry or to assert an outcome in advance. With the same cycle palace, people with different ways of living and handling things can produce very different results.

Four, remember that the more detailed the reading goes down to each hour and each day, the more influencing factors there are, and the harder it is to interpret accurately. That is why the layers of daily and hourly cycles are usually used only as additional reference, not as the sole basis.

An Example Chart: Three Cycle Layers and Twelve Monthly Cycles for 2026

Example chart: male, born 15/3/1990 on the solar calendar (19/2 on the lunar calendar in the year Canh Ngọ), Ngọ hour, Mệnh palace at Dậu. Calculated by exactly the method that the Nhật Nguyệt Tử Vi chart-building tool uses: tiểu hạn starts according to the tam hợp group of the birth year branch, males forward and females backward; nguyệt hạn starts from the lưu Đẩu Quân of the year being examined. Using the method of starting nguyệt hạn from the tiểu hạn palace would give a different monthly table.