Why do Saju apps give different charts?

Compare the calculation rules that commonly make Saju apps disagree near Year, Month, Day, and Hour boundaries.

Short answer: Two apps can disagree because they use different input data, calendar boundaries, time corrections, or school conventions. First locate which pillar changed.

If the Year changed

Check whether the app uses Ipchun, Lunar New Year, or January 1. Qiora uses the exact Ipchun moment for the Saju Year Pillar.

If the Month changed

Check the exact opening Solar Term, birth time zone, and daylight saving history. Saju months do not begin on Gregorian month day one.

If the Day changed

Check the declared day boundary and whether daylight saving time was removed correctly. Qiora currently uses an 11 p.m. boundary in local standard time. Longitude and True Solar Time do not change Qiora’s Day Pillar.

If the Hour changed

Check birth longitude, civil time correction, daylight saving history, and True Solar Time. Qiora applies True Solar Time to the Hour Pillar only. Results near a double-hour boundary are especially sensitive.

If the characters match but interpretations differ

The disagreement is interpretive. Schools may weight Day Master strength, Hidden Stems, combination transformation, Useful God, Special Stars, or Luck Pillar starts differently.

Ask each system to state its rule. A reproducible disagreement is more useful than a mysterious agreement. Save the eight characters, input data, time policy, and calculation version when comparing results.