The honest version.

Bazi (八字, “eight characters”) is a Chinese system of personality and life analysis that's about 3,000 years old. It takes your birth moment — year, month, day, and hour — and turns it into four pairs of Chinese characters representing the elemental forces (Wood, Fire, Earth, Metal, Water) active when you were born.

Where Western astrology focuses on planets and zodiac signs, Bazi focuses on the interactions between those elemental forces — which one anchors your personality, which ones support it, which ones challenge it. The system is deterministic: two people born ten minutes apart in the same city get measurably different charts.

A horoscope buckets you into one of twelve types based on the day you were born. A Bazi reading describes your specific configuration — sixty-plus data points from your exact birth moment, then the relationships between them. There are millions of possible charts; your reading describes yours.

The other difference is tone. We don't do “today Mercury is in retrograde” vague-prediction prose. We write like a friend who happens to know you well — specific, behavioral, honest about friction points instead of comforting platitudes.

The writing is AI. The math is not.

Your chart is computed by a deterministic Bazi engine — the same calculations practitioners have done by hand for centuries, just faster. That math produces a structured snapshot: your Day Master, element balances, active clashes and combinations, Ten Gods, all enumerated explicitly. The AI's job is purely to translate that snapshot into plain English in our house voice. It's forbidden from inventing relationships not present in the math.

This matters because most “AI Bazi” products do it backwards — they hand the LLM raw birth data and ask it to figure out the chart. LLMs are bad at that. Ours doesn't have to guess; the calculations are already done before it starts writing.

For your ownchart, time matters — it sets the Hour Pillar, which adds depth to your reading. If you genuinely don't know, ask your parents, check your birth certificate, or estimate within an hour and rerun the reading later when you have it. Even a rough guess beats nothing.

For a partner'schart in a compatibility reading, we let you leave time and city blank — we'll default to noon and your own city. The reading will be noted as estimated and will lean on the day-pillar dynamics, which are robust to the missing details.

On your device, yes — your most recent birth info is saved in your browser's local storage so you don't have to retype it when you switch between Natal, Compatibility, and Today. You can clear it any time by clearing site data for hopegraph.com.

On our server, no — birth info is sent to the chart endpoint to compute your reading and is not persisted. There are no user accounts in v0. If you buy a reading in a future version, we'll save that specific reading so you can return to its URL, but never a database of birth times.

Three classical conventions disagree across tools, and most online Bazi calculators don't document which they use:

1. True solar time vs. clock time. The classical system uses true solar time at your birth location, which can differ from clock time by up to half an hour depending on longitude. We apply this correction.
2. Daylight Saving Time. The classical practice ignores DST — the meridian is fixed to standard time. We follow that convention.
3. The late-Zi hour rule.If you were born between 11 PM and midnight, classical Western Bazi keeps the day pillar at today's date but uses tomorrow's stem for the hour pillar. We follow this; some tools advance the entire day instead.

If you compared us to a tool that does any of these differently, your pillars may shift by one position. The reading is still correct; it's just a different convention.

As a self-reflection tool, yes. The archetypes are sharp, the friction points are usually recognizable, and the language is built to be useful for thinking about yourself and the people around you.

As predictive advice about specific events — what date to start a business, who to marry, whether to take a job — no. We don't do that, and you should be skeptical of any Bazi tool that does. This is for entertainment and self-reflection. If you're facing a real decision, talk to a real person.