Fate consists of two parts: "Ming" (destiny), which is static and innate, like a piece of gold that is naturally valuable and cherished; and "Yun" (luck), which is dynamic and changes over time. The same piece of gold may have different fates due to its luck. Some gold remains buried in the sand, no matter how heavy or high quality it is, it can never be discovered or used. This is called having good destiny but bad luck. On the other hand, some small pieces of gold, although not very high quality or heavy, are used in important ways, such as being used in the tip of a pen, which significantly increases their value. This is called having good destiny and good luck (or bad destiny but good luck).

The major luck periods change every ten years, hence the saying "Ten years east, ten years west." Therefore, it is essential for a person to know when they will have good luck and when they will face misfortune, in order to seek benefits and avoid harm. When a person's financial and career luck is prosperous, it means they have finally reached the peak after relentless efforts, experiencing a sense of joy that cannot be described fully. However, one cannot stay at the peak forever. From there, any direction is downhill, meaning entering a period of decline. When a person is at the lowest point in life, going either way is uphill, meaning entering a period of good fortune, which is known as finding life in an emergency.

The four pillars represent the destiny, while the major luck represents the flow of fortune. Together, the destiny and the luck determine a person's entire fate. The major luck is determined based on the month pillar of the four pillars, with distinctions between male and female, and differences in calculating the number of days for starting the major luck periods.

Eight Characters Major Luck Calculation: Male born in a yang year follows the forward direction, while female born in a yang year follows the reverse direction. Normally, eight steps of major luck are calculated. For example, if a male is born in the year of Geng Xu (庚戌) and the month of Ji Mao (己卯), he would have the following major luck periods: Geng Chen (庚辰), Xin Si (辛巳), Ren Wu (壬午), Gui Wei (癸未), Jia Shen (甲申), Yi You (乙酉), Bing Xu (丙戌), and Ding Hai (丁亥). If a female is born in the year of Geng Xu (庚戌) and the month of Ji Mao (己卯), her major luck periods would be: Wu Yin (戊寅), Ding Chou (丁丑), Bing Zi (丙子), Yi Hai (乙亥), Jia Xu (甲戌), Gui You (癸酉), Ren Shen (壬申), and Xin Wei (辛未). If a male is born in the year of Ding You (丁酉) and the month of Jia Chen (甲辰), his major luck periods would be: Gui Mao (癸卯), Ren Yin (壬寅), Xin Chou (辛丑), Geng Zi (庚子), Ji Hai (己亥), Wu Xu (戊戌), Ding You (丁酉), and Bing Shen (丙申). If a female is born in the year of Ding You (丁酉) and the month of Jia Chen (甲辰), her major luck periods would be: Yi Si (乙巳), Bing Wu (丙午), Ding Wei (丁未), Wu Shen (戊申), Ji You (己酉), Geng Xu (庚戌), Xin Hai (辛亥), and Ren Zi (壬子).

The method for calculating the starting age of major luck is based on three days equaling one year, meaning one day equals four months, and one hour equals five days. When calculating, for example, if the total number of days to start major luck is 18 days, divided by 3 gives 6, meaning the person starts major luck at the age of 6. If it is 19 days, then it is 6 years and 4 months. Each decade corresponds to one major luck period. Calculating the number of days for starting major luck is based on the month of the birth date, and the direction (forward or reverse) is determined according to gender. For a male born in a yang year, the calculation starts from the birth date to the end of the current month's term. For example, if a male is born on April 21st, 1995, the month term is Qingming (the Clear and Bright Festival), which ends just before the Start of Summer (Xiaoxia) in May. From the 21st, count to the 9th of May when Qingming ends and the Start of Summer begins, totaling 17 days. Divided by 3, this means starting major luck at 5 years and 8 months. If a female is born on the same day, count backward from the 21st to the 9th of April, which marks the beginning of the Start of Summer, totaling 14 days. Divided by 3, this means starting major luck at 4 years and 8 months. For a female born in a yin year, the calculation is the same as a male born in a yang year, and for a male born in a yin year, it is the same as a female born in a yang year.

Every ten years comes a new major luck period, which includes the ten-year cycle of the ten heavenly stems. Although the major luck stem may bring good fortune, the annual luck will not always be the same. The best years are those when one receives significant support, but these years may also be affected by combinations such as punishment, conflict, destruction, and harmony, which may enhance or weaken the supporting elements. In the years when the supporting elements are harmed or weakened, there may be some difficulties, but since the major luck stem is favorable, these difficulties are temporary. Conversely, if the major luck stem is unfavorable, the situation is the opposite.

The stems and branches of the major luck are interrelated. If the stems and branches have a mutual generation or mutual destruction relationship, it will either increase the good fortune or the bad fortune. If the upper stem destroys the lower branch, it will drain the energy of the upper stem. If the upper stem generates the lower branch, it will drain the energy of the upper stem. If the lower branch destroys the upper stem, it will suppress the energy of the upper stem. If the lower branch generates the upper stem or is the same as the upper stem, it will provide support to the upper stem. Additionally, the major luck and the annual luck are like the fifth and sixth pillars, participating in the overall balance of the four pillars, and directly indicating the good or bad fortune in each ten-year period and the annual luck.

The major luck determines the fortune of ten years, while the minor luck governs the fortune of one year. Minor luck can complement the shortcomings of the major luck, annual luck, and four pillars, or it can contradict them.

The method of calculating minor luck is based on the principle that males born in a yang year follow the forward direction, while females born in a yang year follow the reverse direction. It starts from the time pillar. For example, if a male is born on May 6th, 1998 (Wu Yin year, Ren Zi hour), his minor luck for the first year is Gui Chou (癸丑), for the second year it is Jia Yin (甲寅), and so on, continuing in the forward direction. If a female is born on the same day, her minor luck for the first year is Xin Hai (辛亥), for the second year it is Geng Xu (庚戌), and so on, moving in the reverse direction. The calculation of minor luck is based on the actual age, counting one year for each year.