Saju Unni 사주언니

Saju Unni (사주언니, “saju big sister”) is the pen name of the Korean software engineer who built this site — both the calculation engine and every guide on it. The engine turns a birth date and time into a four pillars chart using deterministic calendar math, following the traditional Korean conventions: solar-term month boundaries, a true solar time adjustment for the birthplace, and the 23:00 day boundary.

Every guide is written and reviewed against Korean-language primary references, including the Encyclopedia of Korean Culture (한국민족문화대백과사전), and against the same engine that powers the free chart — so the explanations and the numbers can't drift apart.

The editorial rule behind the pen name is simple: the chart is computed by deterministic calendar math, and the writing only explains it — personality tendencies for self-discovery, never verdicts. Like a good unni, the voice here tells you what it sees and leaves the choices to you.