Two names for a shared writing system
Saju (사주, 四柱) and Bazi (八字) both write a birth moment as four pillars, each pairing a Heavenly Stem with an Earthly Branch. The eight characters are the same kind of table. Korean public writing usually says Saju or Saju-palja; Chinese public writing usually says Bazi or Shengchen Bazi. The difference in everyday speech is not proof that the calendars are unrelated. It is a difference of language and of the schools that taught the table.
What the calendar parts have in common
Both traditions use the ten stems, the twelve branches, the sixty-pair cycle, and the twenty-four solar terms that bound the Month Pillar. Those pieces come from East Asian calendrical practice, not from a modern personality test. A national almanac that lists solar-term instants is a source for the month boundary. It is not a source for a career forecast. Keeping that split is the main editorial job of these pages.
Where programs quietly disagree
Two calculators can share the same names and still disagree at edges: true solar time versus standard zone time, how early 子時 is split across calendar dates, and which solar-term table they loaded. Korean and Chinese desktop programs have each accumulated house rules. When results differ, the useful question is which input and which rule were applied, not which national label is “correct.”
How this site uses the words
MUN’s public guides use Saju as the Korean name of the Four Pillars table and mention Bazi when a reader arrives with that search term. The calculator applies one documented calendar path. It does not switch hidden rules because the visitor’s interface language changed. Traditional interpretive vocabulary — ten gods, useful gods, luck cycles — is labeled as tradition on both sides of the language line.
What a shared calendar does not prove
A shared notation does not make a personal prediction scientific. Korean Saju consultation and Chinese Bazi consultation are cultural practices. Historical offices that kept almanacs do not convert those practices into laboratory evidence. Public pages on this site therefore explain structure and name their calendar sources. They do not claim that one school’s reading of a day master is an empirical finding.
How to read a comparison without turning it into a contest
If you compare a Korean page and a Chinese page, start with the inputs: calendar type, place, and whether an hour was given. Then compare the printed pillars. Only after the tables match is it worth asking why two commentaries diverge. Commentary divergence is expected in a tradition with many schools. It is not a defect in the solar-term list.