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AI Saju Prompt: How to Ask ChatGPT, Gemini or Claude About Your Chart Accurately

Lots of people now ask ChatGPT, Gemini or Claude to read their saju or BaZi chart. Give an AI just your birthday and say "read my chart", though, and you often get a convincing reading of the wrong chart. Here is why — and how to ask so the answer is built on the right eight characters.

Make my AI saju prompt — free

Why does just asking go wrong?

AIs write well, but almanac work — dates and astronomy — is where they slip. A reading can only start once the eight characters are right, and the first button is often done up wrong.

• The year changes at Lichun, not January 1. If you were born in January or early February, your year pillar and zodiac sign may belong to the previous year. AIs often use the calendar year or Lunar New Year instead.
• The month changes at the solar terms, not on the 1st. Born within a day of a solar term such as Jingzhe or Qingming, your month pillar shifts by one — and with it your chart structure and useful element.
• Birth time needs correcting. Saju uses local solar time. Clock time in your time zone can be far from the sun's: the sun runs about 16 minutes ahead of Eastern Time in Boston and about 32 minutes behind it in Detroit. Daylight saving time has to come off too — and US history includes year-round "war time" in 1942–45 and year-round DST in 1974. Born between 11 pm and 1 am, you also need a rule for which day the 子 hour belongs to.
• Lunar and leap-month conversions go wrong. If you only know a lunar birthday, being off by one day in the conversion changes your day pillar.
• Luck-pillar ages are fiddly. The starting age of your 10-year luck is counted from the days between your birth and the next (or previous) solar term. AIs often skip or botch this.
• The answer changes every time. With no calculation behind it, the same question gets a different chart each time — and tends to drift towards pleasant generalities.

Five marks of a good saju prompt

1. Hand over the finished chart. Give the eight characters with their ten gods, hidden stems and element strength instead of a birth date, and the AI has nothing to calculate.
2. State how it was calculated. Month pillars by solar term, year pillars from Lichun, longitude corrected — say so, and the AI will not quietly recalculate.
3. Include the 10-year and annual luck. "What about this year?" or "When should I change jobs?" cannot be answered without them.
4. Ask for reasons. "Name the characters behind every answer" turns vague compliments into a reading you can check.
5. One specific question at a time. "When is a good time to change jobs in my current 10-year luck?" gets a deeper answer than "Tell me everything".

A prompt template you can use now

Fill in the [ ] parts. If filling in the chart and luck yourself is hard, Data Saju builds the whole prompt for you from your date of birth.

You are a friendly counsellor who knows Korean saju (Four Pillars / BaZi) well.
Below is my chart, calculated with an almanac including solar terms and longitude.
Do not recalculate it from a birth date — use these values as they are.

[My chart]
- Gender [ ], born [ ]
- Four Pillars (hour / day / month / year): [ ]
- Ten gods, hidden stems, life stages: [ ]
- Element strength, chart strength, structure, useful element: [ ]
- 10-year luck pillars and the current one: [ ]
- This year's and next year's annual pillars: [ ]

[Answer rules]
1. Use the values above as given; do not recalculate.
2. Name the characters behind every answer (ten gods, elements, combinations, luck).
3. Describe tendencies and ways to prepare rather than "good" or "bad".

[Question]
[One thing you want to know]

Making the prompt with Data Saju

1. Enter your date and time of birth and your birthplace. Solar terms, longitude and daylight saving are corrected automatically.
2. At the bottom of the complete reading or any report (money, career, love, compatibility …), tap Prompt for my own AI.
3. Copy it into a new chat in your AI and change only the [Question] at the bottom. Made from a compatibility report, it includes the other person's chart too.

The prompt contains no birth date or name — only the eight characters and the birth year — so pasting it into an AI does not identify you.

Make my AI saju prompt — free

FAQ

Is it really free? Yes. The chart, the reports and the prompt are all free, with no sign-up.

Which AIs does it work with? Any chat AI that takes long messages — ChatGPT, Gemini, Claude and others.

How is it different from asking Master Han? Master Han is this site's AI saju reader, which calculates luck with our almanac engine as it answers (3 free questions a day). To go longer or ask many times, carry on in your own AI with the prompt.

The terms in the prompt are hard. They are explained in plain English in the ten gods, the useful element, luck pillars and chart structure.