1. Chart Calculation Is Exact
The mechanical part — converting your solar birth date to the lunar calendar, placing the Life and Body Palace, positioning all 14 major stars, and calculating the Four Transformations — is a fixed, deterministic algorithm. Given the same birth date, time, and gender, any correctly-built calculator (this one included) will produce an identical chart every time. This part of accurate zi wei dou shu calculator claims is straightforward to verify. One simplification worth knowing: this calculator uses your entered clock time and time zone directly, without adjusting for true solar time (the small offset between clock time and the sun's actual position based on your exact longitude). For most locations this offset is a few minutes and won't change your hour-based Palace placement — but if your birth time falls close to a two-hour block boundary, a longitude-based adjustment could shift it into the adjacent block.
2. Where Accuracy Actually Depends on You
The two biggest sources of error are not the calculator — they're your input data. An unknown or approximate birth time can shift your Life Palace and the Hour Pillar-equivalent placements significantly, and time zone or daylight-saving confusion around your birth time can shift the calculated Chinese hour block entirely. Double-check your birth certificate time before treating any reading as definitive.
3. What "Accuracy" Means for Interpretation
Interpretation accuracy is a different question from calculation accuracy. Zi Wei Dou Shu describes tendencies and domains, not specific predicted events — a Career Palace reading that says you're suited to leadership doesn't predict a specific job title or promotion date. Evaluate a reading's usefulness the way you would any self-reflection tool: does the general personality and pattern description ring true, not whether it "predicted" a specific headline event.