Korea, from Chinese calendrics · codified ~9th–12th century
Saju · Four Pillars
Reads the calendar itself: your birth year, month, day and hour, each expressed as a pair of cosmic characters.
Where it comes from
Saju (사주, “four pillars”) is the Korean practice of the Chinese art BaZi, built on the sexagenary calendar that has counted time in East Asia for over two millennia. Codified between the Tang and Song dynasties, it remains part of everyday life in Korea — consulted for names, weddings and career turns.
What we compute from your birth
We convert your birth moment into the traditional calendar: four pillars (year, month, day, hour), each a heavenly stem and earthly branch; the day master that anchors the chart; the balance of the five elements; and the ten-year luck cycles, sequenced by the traditional gender rule.
The positions and cycles are computed with real astronomy and calendar arithmetic — the interpretation never invents a number.
If it's new to you
Where Western astrology reads the sky, Saju reads time. There are no planets here — the calendar cycle itself carries the qualities, the way a vintage year carries a wine. Your “day master” plays the role a Sun sign plays: the self the rest of the chart feeds or drains.
Key terms
- Day master
- The heavenly stem of your birth day — the chart's “you”. Everything else is read as supporting, draining or challenging it.
- Stems & branches
- Ten heavenly stems and twelve earthly branches (the zodiac animals) that combine into the 60-unit calendar cycle.
- Five elements
- Wood, Fire, Earth, Metal, Water — every stem and branch carries one; their balance shapes the reading.
- Four pillars
- Year, month, day and hour pillars — ancestry, upbringing, self and later life in the classical scheme.
- Luck cycles (daeun)
- Ten-year chapters that recolor the chart as life unfolds — the timing layer of Saju.