chinese-vedic-astrology

name	chinese-vedic-astrology
description	Calculate and interpret Chinese BaZi Four Pillars / Chinese zodiac and Vedic Jyotish charts including nakshatras, dashas, yogas, and ayanamsa selection. Use when someone asks about Eastern astrology systems, their Chinese zodiac animal, BaZi, sidereal/Vedic chart, nakshatra, or dasha.
version	1.0.0
updated	"2026-05-23T00:00:00.000Z"

Chinese & Vedic Astrology

Two distinct Eastern systems. Don't conflate them — Chinese astrology is based on the lunisolar calendar and Five Elements; Vedic is sidereal and tied to the Nakshatra (lunar mansion) system.

When to Use Which

Question	System
"What's my Chinese zodiac animal?"	Chinese (basic)
"What's my BaZi / Four Pillars / Eight Characters?"	Chinese BaZi
"Element balance / lucky element?"	Chinese BaZi
"What's my Vedic chart / Jyotish?"	Vedic
"What's my nakshatra / lunar mansion?"	Vedic
"What dasha am I in?"	Vedic
"Tropical vs sidereal — what's the difference for me?"	Vedic

Required Information

For both:

1. Full birth date
2. Birth time (for BaZi, hour pillar requires this; for Vedic, all houses + nakshatra are time-sensitive)
3. Birth location

Standard Procedure for Birth-Data Endpoints

Any endpoint that takes a birth chart (natal, synastry, composite, transits, returns, progressions, Human Design, Vedic, ACG) MUST follow this sequence. Skipping any step produces a wrong chart — usually wrong by hours of arc.

Step 1 — Resolve location to coordinates

If you don't already have precise lat/lon, call:

GET /location/autocomplete?query=<city, country>&limit=5

Confirm the right hit with the user if there's ambiguity (e.g. "Portland, OR" vs "Portland, ME"). Record the latitude and longitude of the chosen result.

Step 2 — Resolve timezone for that location AT THE BIRTH DATE

Historical timezone rules matter. A city's UTC offset in 1962 may differ from today (DST rules, war time, jurisdiction changes). Always look up the timezone for the specific birth date.

POST /timezone/lookup
{ "latitude": <lat>, "longitude": <lon> }

Response gives an IANA timezone string like "America/Los_Angeles". The BirthLocation field below REQUIRES this — it is not optional.

Step 3 — Build the request body

The SubjectRequest schema requires birth_datetime, birth_location, and name. The IANA timezone goes into birth_location.timezone:

{
  "subject": {
    "name": "Subject",
    "birth_datetime": { "iso": "1990-04-15T14:30:00" },
    "birth_location": {
      "latitude": 41.8781,
      "longitude": -87.6298,
      "timezone": "America/Chicago",
      "city": "Chicago",
      "country": "United States"
    }
  }
}

The iso field is the local civil time at the birth location. The API handles the conversion to UTC using the supplied IANA timezone. Do not pre-convert to UTC and do not pass an offset suffix on the iso string unless the user explicitly knows it.

Step 4 — Choose house system (ask if appropriate)

The natal chart endpoint defaults to Placidus. Before computing, briefly ask:

"I'll use Placidus houses by default (the most common modern Western system). If you prefer a different system — Whole Sign (Hellenistic/traditional), Koch, Equal, Campanus, Regiomontanus, or Porphyry — just say so."

Once chosen, pass it through configuration.house_system on the request.

Step 5 — Always request format=llm unless raw JSON is requested

This reduces token usage by ~73% and gives you a readable, interpretable response. Add ?format=llm to the URL.

Time-unknown handling

If the user doesn't know their birth time:

• Sun sign, outer planets, North/South Node sign — reliable.
• Moon sign — only reliable to within ~12 hours. If the user knows roughly morning/afternoon/evening, it usually narrows enough.
• Rising sign, all house placements, Midheaven — unreliable. Do not interpret these without a time.
• Default fallback: use 12:00 noon local. Disclose: "Without a birth time, I'm using noon as a placeholder. Your rising sign, house placements, and Moon sign may not be accurate. The rest of the chart is still meaningful."

For Human Design, type/strategy/authority/profile depend on precise time — flag any time uncertainty and suggest the user rectify with a Human Design analyst or rectification service before relying on these results.

---

Chinese Astrology

Chinese Zodiac (Surface)

Just animal + element from year of birth:

POST /chinese/zodiac

Returns the year animal (12-year cycle) and element (5-element cycle = 60-year zodiac).

12 animals: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig 5 elements: Wood, Fire, Earth, Metal, Water

BaZi — Four Pillars of Destiny

The deep Chinese system. Four pillars: Year, Month, Day, Hour. Each pillar has a Heavenly Stem + Earthly Branch (a stem-branch pair). The Day Master (the Stem of the Day Pillar) is the user's core self.

POST /chinese/bazi

Body:

{
  "year": 1990,
  "month": 4,
  "day": 15,
  "hour": 14
}

BaZi uses solar terms, not the standard Gregorian calendar. The calculation handles this automatically. The hour is the local solar hour at the birth location — pass the local clock hour, the engine corrects.

How to Read BaZi

1. Day Master — the user's identity. State the stem (e.g. "Yang Wood Jia"). This anchors everything.
2. Element Balance — which elements are strong/weak/missing. Call:

   POST /chinese/bazi/element-balance
   

   The user's Useful God (favorable element) and Restrictive God (unfavorable) emerge from this.
3. Ten Gods — the 10 archetypal relationships between Day Master and other pillars (Friend, Rival, Output, Wealth, Authority, Resource, etc.):

   POST /chinese/bazi/ten-gods
   

4. Luck Pillars (Da Yun) — 10-year life cycles, each with its own stem-branch:

   POST /chinese/bazi/luck-pillars
   

5. Annual Pillar — current-year influence:

   POST /chinese/bazi/annual-pillar
   

6. Compatibility — between two BaZi charts:

   POST /chinese/bazi/compatibility
   

Interpretation Order

• Lead with Day Master and what it means (e.g. "Yang Wood Jia is the great tree — rooted, principled, slow but steady growth").
• Then element balance: "Your chart is strong in Fire and weak in Water — your Useful God is Water, meaning Water-element environments, careers, and people support you."
• Walk through Year/Month/Day/Hour pillar themes (ancestry / parents+youth / self+spouse / children+later life).
• Note the current Luck Pillar — the 10-year backdrop.
• Mention 2–3 of the strongest Ten Gods relationships.

---

Vedic Astrology (Jyotish)

Ayanamsa — Ask First

Vedic charts use the sidereal zodiac (fixed-star reference) rather than tropical (seasonal). The offset between tropical and sidereal is called the ayanamsa. Different schools use different ayanamsas — they shift sign and nakshatra boundaries by minutes to a full degree, which matters for the Moon's nakshatra.

Before computing, ask:

"Which ayanamsa would you like? Lahiri is the modern standard (used by the Indian Government Ephemeris). Other options: Raman (B.V. Raman school), Krishnamurti (KP system), or Fagan-Bradley (Western sidereal)."

Default to Lahiri if the user has no preference.

Compute

POST /vedic/chart?format=llm

Body:

{
  "datetime_utc": "1990-04-15T19:30:00Z",
  "latitude": 41.8781,
  "longitude": -87.6298,
  "ayanamsa": "lahiri"
}

Vedic chart uses datetime_utc directly — convert local birth time → UTC using the IANA timezone from the Standard Procedure.

How to Read a Vedic Chart

Walk through in order:

1. Lagna (Ascendant) & Lagna Lord

The rising sign at birth — the most important point in Vedic astrology. The Lagna Lord (the planet ruling the rising sign) and its placement determines life direction.

2. The Moon and Nakshatra

The Moon's nakshatra (one of 27 lunar mansions) is read MORE than the Sun in Vedic. State:

• Moon sign (Rasi)
• Moon nakshatra (one of 27, e.g. Rohini, Ashwini, Magha)
• Pada (which of 4 quarters of the nakshatra)

The nakshatra ruler and its placement deeply colors the personality.

3. The Nine Grahas (Planets)

Note: Vedic uses 9 grahas — the 7 visible planets plus Rahu (North Node) and Ketu (South Node). It does NOT use Uranus, Neptune, Pluto (some modern Vedic astrologers do; default is the classical 9).

For each graha, note: sign, house from Lagna, nakshatra placement, dignity (exalted, debilitated, own sign, friend's sign, enemy's sign), retrograde status.

4. Mahadasha (Major Period)

The Vimshottari dasha system divides life into 9 planetary periods. Each is 6–20 years. State:

• Current Mahadasha (e.g. "Saturn Mahadasha, 19 years total, you're 7 years in")
• Current Antardasha (sub-period within Mahadasha)
• What this period emphasizes

5. Yogas (Planetary Combinations)

Special combinations that confer specific outcomes. Famous ones:

• Raja Yogas — kingly combinations (success, status)
• Dhana Yogas — wealth combinations
• Gajakesari Yoga — Jupiter-Moon in mutual kendras (good fortune, knowledge)
• Neecha Bhanga Raja Yoga — debilitation cancellation (rags to riches)

Highlight any prominent yogas in the chart.

6. Divisional Charts (Vargas)

If asked for depth, mention:

• D-9 / Navamsa — marriage, spiritual path, true potential of each planet
• D-10 / Dasamsa — career
• D-7 / Saptamsa — children
• D-12 / Dwadasamsa — parents

Tropical vs Sidereal — the Common Question

Users often ask why their Vedic Sun sign differs from their Western Sun sign. Explain:

"Western astrology uses the tropical zodiac, locked to the seasons (Aries always starts at the spring equinox). Vedic uses the sidereal zodiac, locked to the actual fixed stars. The two have drifted apart by ~24° over 2000 years. Your Vedic Sun is one sign earlier than your Western Sun roughly 75% of the time. Neither is 'right' — they're two different reference frames asking different questions."

How to Frame Astrological Readings

• Symbolic, not deterministic. Astrology maps patterns and tendencies; it does not predict fixed outcomes. Every placement has light and shadow expressions, and conscious effort changes how a chart plays out.
• Not a substitute for professional advice. Astrology is not medical, legal, financial, or psychotherapeutic guidance. If a user is in crisis or asking about real medical / legal / financial decisions, recommend they see a qualified professional in that field.
• Honor the whole chart. No single placement defines a person. Synthesize across signs, houses, aspects, and dignities before offering interpretation.
• Be specific, not generic. Cite the actual placement and explain its meaning in context, rather than reciting trait lists.
• Be balanced. Don't flatter or doom-cast. Hard aspects are growth-producing; soft aspects can become laziness.
• Stay curious. If a user pushes back on a reading, that pushback is data — chart interpretations are dialogues, not verdicts.

Example Flows

"What's my BaZi?"

1. Standard Procedure (mainly for the local hour — geocoding still useful for solar time correction at extreme longitudes)
2. POST /chinese/bazi with year/month/day/local-hour
3. POST /chinese/bazi/element-balance for the Useful God
4. Lead with Day Master + Useful God; walk pillars

"What's my nakshatra?"

1. Ask preferred ayanamsa (default Lahiri)
2. Standard Procedure → UTC
3. POST /vedic/chart with ayanamsa: "lahiri"
4. Lead with Moon nakshatra + pada, then Lagna, then current Mahadasha