The Four Pillars of Destiny, or "Bazi" in Chinese, is essentially a system that uses heavenly stems and earthly branches to represent a person's birth year, month, day, and hour, resulting in eight characters—hence the name "Bazi." These four time units correspond to four pillars: the Year Pillar, Month Pillar, Day Pillar, and Hour Pillar.

There are ten Heavenly Stems, which are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui in sequence. The twelve Earthly Branches are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai. These stems and branches combine to form 60 unique pairs known as the "Sixty Jiazi," used to record time and convey distinct energetic information. For example, if a person was born at 9 a.m. on May 10, 2024, according to the traditional Chinese Stem-Branch calendar, 2024 is the year of Jiachen, May is the month of Jisi, the 10th is the day of Yisi, and 9 a.m. is the hour of Xinsi. Thus, their Four Pillars of Destiny would be "Jiachen, Jisi, Yisi, Xinsi."

Each Heavenly Stem and Earthly Branch embodies unique Five Elements attributes:

In the Heavenly Stem, Jia and Yi belong to Wood; Bing and Ding to Fire; Wu and Ji to Earth; Geng and Xin to Metal; Ren and Gui to Water. Among the Earthly Branches, Zi and Hai belong to Water; Yin and Mao to Wood; Si and Wu to Fire; Shen and You to Metal; Chen, Xu, Chou, and Wei to Earth. By analyzing the interactions and changes of these Five Elements attributes, one can interpret trends in a person's fate.

The Four Pillars of Destiny is more than a mere record of time or a combination of symbols. It embodies the profound philosophical thoughts of ancient China, with its core being the theory of Yin-Yang and the Five Elements. Ancient Chinese believed that all things in the universe are formed by the interaction of two opposing forces—Yin and Yang, and that the balance and harmony between Yin and Yang constitute the foundation for the stable development of all things.

In a person’s Bazi, the distribution and strength of the Five Elements reflect their inborn fortune-endowed qualities and potential energetic traits. For instance, those with a dominant Wood element in their Bazi may have a tenacious character and strong vitality, as Wood symbolizes the power of growth and upward movement; while those with a prominent Water element might be quick-witted and emotionally rich, just like water, which is agile and inclusive.By analyzing the relationships between Yin-Yang and the Five Elements in the Four Pillars of Destiny, one can infer the potential opportunities and challenges a person may encounter in aspects such as career, wealth, relationships, and health.