What is Ri Yue Tong Lin (Sun and Moon Together)?

Tai Yang and Tai Yin: one the light of day, the other the light of night. When the two sit in the same palace, the ancients called it Ri Yue Tong Lin (the sun and moon arriving together). The combination comes with a special way of reading it: with two kinds of light in one palace, which one shines brighter depends on whether you were born by day or at night. To see whether you have it, draw your chart.

The conditions for Ri Yue Tong Lin

• Tai Yang and Tai Yin share a palace, and it holds only these two main stars.
• Tai Yang and Tai Yin only share a palace in Chou or Wei.
• Any of the twelve palaces counts, not only the Life Palace.

Because the palace isn't restricted, the combination is very common: about 1 chart in 6 has it in some palace; in the Life Palace, about 1 in 65.

Born by day or at night

In the two positions, the two stars' brightness is exactly reversed:

Chou is after midnight, with the moon bright and the sun not yet up; Wei is afternoon, with the sun still giving light and the moon not yet risen. When volume three of the Quan Shu discusses the sun and moon, it has this commentary:

When the sun and moon share a palace, look at the time of birth. By day, look to Tai Yang; by night, to Tai Yin.

Xingge reads it this way:

• Sun and moon in Chou, born at night: you connect with Tai Yin's light, and this palace's affairs go more smoothly.
• Sun and moon in Wei, born by day: you connect with Tai Yang's light, and this palace's affairs go more smoothly.
• The other way round, Chou with a day birth or Wei with a night birth, you get the weaker side, and this palace needs a little more patience.

Xingge's "day" runs from the Mao hour to the Shen hour (roughly 5 a.m. to 5 p.m.); the rest counts as night.

What the classics say, and where Xingge differs

The Gu Sui Fu in volume one says:

The sun and moon arriving together: office as a marquis or earl.

But judging by the original text, the classics' idea of Ri Yue Tong Lin may have been much narrower. The section on noble patterns only says "see the note above" under this entry, and volume three's most specific line on the sun and moon sharing a palace is:

Sun and moon together in Wei, with the Life Palace in Chou: the makings of a marquis or earl.

Meaning Tai Yang and Tai Yin in Wei, with the Life Palace opposite in Chou, the sun and moon shining into the Life Palace from across the chart: the makings of a marquis or earl, the same words as the rhapsody's "office as a marquis or earl." Volume three also says:

The sun and moon guarding the Life Palace is not as good as shining in together.

With the sun and moon sitting directly in the Life Palace, the ancients actually felt it was not as good as shining in from outside.

So the classics' Ri Yue Tong Lin seems to describe the chart with "the Life Palace in Chou and the sun and moon in Wei shining across"; Xingge widens it to "the sun and moon together in any palace," then uses day or night birth to judge how smoothly it goes. The emphasis differs: the classics judge how high the chart ranks, Xingge whether that palace's affairs run smoothly.

In different palaces

Wherever Ri Yue Tong Lin sits, that palace has a "two kinds of light" quality: reason and feeling, outward and inward, giving and receiving. When it goes well, both sides are covered; when it doesn't, they pull against each other.

• Life Palace: your character has both Tai Yang's warmth and Tai Yin's sensitivity, often switching between outgoing and inward.
• Spouse Palace: in love you want both to give and to be looked after; finding the balance between the two matters.
• Wealth Palace: you earn through both reputation and accumulation; both ways work for you.
• Property Palace: home is both lively and quiet; where you live often has two moods.

In the classics, Tai Yang and Tai Yin also stand for father and mother (male and female elders), so with Ri Yue Tong Lin in the Parents Palace, some practitioners also read it for your relationship with both parents.

What strengthens it and what weakens it

• Strengthens: the star whose light you connect with takes Hua Lu, Hua Quan or Hua Ke, such as Tai Yin taking Hua Lu in Ding years or Tai Yang taking Hua Lu in Geng years; Zuo Fu, You Bi, Wen Chang, Wen Qu, Tian Kui or Tian Yue in the same palace or the San Fang.
• Weakens: Tai Yang taking Hua Ji in Jia years or Tai Yin in Yi years puts Hua Ji in that palace; Qing Yang, Tuo Luo, Huo Xing, Ling Xing, Di Kong or Di Jie in the same palace make the pull between the two lights more evident.

How to check whether you have Ri Yue Tong Lin

1. Draw your chart and find the square where Tai Yang and Tai Yin share a palace (Chou or Wei).
2. See which of your palaces it is.
3. Then compare with your birth hour: Chou with a night birth, or Wei with a day birth, is the kind that connects with the light.

A Life Palace in Chou with the sun and moon in Wei shining across is the classics' Ri Yue Tong Lin. To understand the two stars, see the Tai Yang and Tai Yin lesson.

Common questions

What does Ri Yue Tong Lin mean?

Tai Yang and Tai Yin sharing a palace is called Ri Yue Tong Lin, and it only happens in Chou or Wei. The Quan Shu says "the sun and moon arriving together: office as a marquis or earl"; volume three's most specific line is "sun and moon together in Wei, with the Life Palace in Chou: the makings of a marquis or earl," the sun and moon in Wei shining into the Life Palace in Chou from opposite.

Does Ri Yue Tong Lin depend on being born by day or at night?

Yes. Volume three of the Quan Shu says "when the sun and moon share a palace, look at the time of birth. By day, look to Tai Yang; by night, to Tai Yin." In Chou, Tai Yin is bright, so night births connect better; in Wei, Tai Yang is bright, so day births connect better.

Is Ri Yue Tong Lin in the Life Palace good?

The sun and moon in the Life Palace make for a character with both reason and feeling. But the classics say "the sun and moon guarding the Life Palace is not as good as shining in together," meaning sitting directly in the Life Palace is less good than shining in from the opposite palace or the trines. People with it in the Life Palace especially need to look at their birth hour and the stars in the San Fang.

Is Ri Yue Tong Lin common?

With Tai Yang and Tai Yin together in Chou or Wei in any of the twelve palaces, about 1 chart in 6 has it. In the Life Palace, about 1 in 65; the classics' "Life Palace in Chou, sun and moon in Wei" is rarer still.