The four pillars
Your zodiac year may not start on January 1
Here is the twist most people miss: the BaZi year does not turn on January 1, and not on Chinese New Year either. It turns at the Start of Spring (立春 lì chūn), around February 4. If you were born in late January or very early February, your true zodiac animal may not be the one the calendar gave you. That is because BaZi runs on the sun: the year and the month are set by the solar seasons, not the ordinary calendar.
A chart casts one pillar for the year, month, day, and hour of birth. Each pillar is a Heavenly Stem (an element) above an Earthly Branch (a zodiac animal), so four pillars make eight characters. Tap any branch below to see its animal, its season, and the hours it rules.
What each pillar holds
Four rooms, three layers deep
The four rooms
The year speaks to ancestry and early life, the month to upbringing and career ground, the day to the self and the partner, and the hour to later life and what you create.
Three layers deep
Each pillar has a visible stem (the outward face), a visible branch (the ground), and one to three hidden stems inside the branch (the inner reserves). That third layer is where the real reading happens.
Why the hour matters. The hour pillar is about a quarter of the chart, and a birth near midnight can even shift the day pillar. When the birth time is uncertain, that quarter is read as provisional, exactly the caution a careful reader keeps in mind.