The husband's day stem is an "Yang Stem," while the wife's day stem is a "Yin Stem," which aligns with the principle of Yin and Yang in the universe. Especially when the two day stems are compatible in terms of Yin and Yang, the couple will be very affectionate. The Book of Changes states: "Heaven moves strongly, and the gentleman should strive unceasingly; Earth is vast and fertile, and the gentleman should carry all things with virtue." This fully illustrates that men are Yang, and thus the man's day stem should be an Yang stem, while women are Yin, and thus the woman's day stem should be a Yin stem. When Yin and Yang combine, the couple will live in harmony, with the husband leading and the wife following, resulting in a happy family and smooth progress in all matters.
By emulating the spirit of Yin and Yang in Heaven and Earth, the husband should take responsibility, and the couple should respect each other, which will lead to a lasting marriage. A man with an Yang stem has a pioneering and responsible spirit, while a woman with a Yin stem respects her husband and values everything he does. With mutual respect, the couple will get along better, the family will become smoother, and the children will become more filial. Children raised in such an environment will also have smooth and happy marriages in the future.

Complementary Useful Gods between Spouses

　If the husband's day stem nourishes the wife's day stem, it indicates that the husband loves his wife and is willing to do many things for her. If the wife's day stem nourishes the husband's day stem, it shows that the wife deeply loves her husband and will take good care of his daily life, respecting his choices, etc. For example, if the husband's day stem is Jia Wood and the wife's day stem is Ding Fire, it represents wood nurturing fire, and so on.
People change over time, so love may not last forever. During courtship, we must like each other, and after marriage, we must respect each other. Only this kind of love can last. The things that couples do for each other should not be constantly mentioned, always expecting the other to remember your kindness. That is wrong. If a couple always thinks about their debts of gratitude, the marriage will surely fail. Remember this well.

Before marriage, we carefully observe the other person, gather information, and understand their family background, job, and how they deal with people. Then we can form a marriage. However, even if we know each other well, there may still be conflicts after marriage, and even marital crises. At this point, we need to learn to look the other way, think about why we chose to become a couple in the first place.
Everyone has strengths and weaknesses. Strengths can become weaknesses, and weaknesses can become strengths. Therefore, we should look the other way and respect each other's different styles. It's easy to say, but hard to practice. Only those whose year stems complement or nourish each other will share common goals, cooperate with each other, and benefit mutually. Couples with similar interests should encourage each other, work together to improve and develop, and maintain the relationship. For differences, they should respect and appreciate each other.