The birth chart
The natal chart records the elemental pattern associated with the time of birth. It is used to discuss tendencies, strengths, pressures, and balance.
About BaZi
BaZi (八字) means Eight Characters. It converts a birth moment into Four Pillars: year, month, day, and hour. Each pillar contains a Heavenly Stem and an Earthly Branch.

The birth chart is the starting point. Later periods introduce new stems and branches that are read in relation to that original chart. The chart stays fixed, while the timing around it changes.
The natal chart records the elemental pattern associated with the time of birth. It is used to discuss tendencies, strengths, pressures, and balance.
Ten-year Luck Pillars (大运) and annual cycles (流年) add changing influences. Practitioners study how those incoming stems and branches interact with the birth chart.
Timing changes the conditions
The same seed, soil, and effort can produce different results depending on when the seed is planted. Tomatoes sown in spring have the warmth and daylight they need. The same seeds planted in cold late-autumn soil may fail.
The seed has not changed. The conditions have. BaZi date selection applies this principle to an important action: choose a time when the surrounding conditions support what you want to begin.
Apply the principle