Timing
Beyond the natal chart, BaZi lays out luck pillars (大运, da yun) — successive ten-year stretches, each labeled by a stem-branch pair, traditionally read as the "season" a life moves through. A chart is the terrain; luck pillars are the weather arriving over it.
Each person's sequence is derived from their month pillar and their gender relative to the year's polarity, walking forward or backward through the sexagenary cycle. The first pillar does not start at birth: a start age is computed from the distance to the nearest solar term — conventionally three days count as one year, which is why start ages vary and why a missing birth hour makes the start approximate.
Read as self-reflection, a luck pillar is a framing question: what does this stem-branch season invite, and what does it tax? A wood-heavy season favors beginnings; a metal season favors sorting and decisions. The same event lands differently in different seasons — that is the whole usefulness of the lens.
A fair practice avoids turning seasons into verdicts. Luck pillars describe emphasis, not fate; the terrain metaphor holds — weather matters, and so does the walker.