Li Yih-yuan of the Academia Sinica has written a paper called "Traditional Chinese Cosmology and Modern Business Behavior." In it he notes that at birth each person is assigned a "Celestial Stem" and "Earthly Branch" depending upon the month, year, day, and time of birth. These are the socalled "eight characters."
中研院院士李亦園在「傳統中國宇宙觀與現代企業行為」論文中表示，中國每一個人出生時，就根據年、月、日、時給以天干、地支的記號，是所謂的八字。