Chinese fortune-telling "8 Characters" （生辰八字）

The Four Pillars of Destiny is an important component of Chinese fortune telling. The 'four pillars' refers to the year, month, day and hour pillars of a birthday and birth hour in Chinese solar calendar. It is also known as the 'eight characters of birth time', the Chinese term ”八字“ which means "eight characters" is represented by four pairs of characters respectively saying the year, month, day and hour of a birth time. Two characters in each pair are made up of one character from the Heavenly Stems （天干）and one from the Earthly Branches （地支）. 

Traditionally match-makers would ask for "8 characters" of the marriageable girl & boy, have them evaluated to see whether these two make a good match. If it turns out that they do not match, very likely the marriage arrangement would fail under opposition of parents of both.

 Above picture shows the 12 two-hour periods into which the day was traditionally divided, each 2-hours is called Shichen (时辰), and each being given the name of one of the 12 Earthly Branches. This is the hour info in the "8 Characters".

It has only eight characters, but the relation of the eight characters is very complicated. According to the four pillars' representation theory, year pillar represents ancestors and parents; month pillar represents brothers and sisters; day stem represents oneself; day branch represent spouse; hour pillar represents offspring. In addition, the heavenly stems have their own characteristics which are related to the Five Elements (五行). The missing element in a baby's 'eight characters of birth time' will be usually added into its name as an action of compensation. Among the ten heavenly stems, there are compatible and opposite relations. While among the earthly branches, the relations are more complex, combination, clash, restriction, harm, etc. Abundant relationships may have accurate explanation on the luck of one self or relatives.