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get_date returns five sign blocks under astro_wheels. Each is a different astrology system — not five copies of one answer. Three cut the zodiac into equal 30° signs; two use unequal spans and add a 13th sign, Ophiuchus. On many dates all five agree; on others they land on different sign names. That divergence is expected — a different system, not a wrong answer.

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The five wheels

Always read sign_name (and system_slug) on the wheel you care about. Do not treat sign_no as a universal zodiac index — see Field glossary. Equal vs unequal spans:
  • Equal — 30° per sign, 12 signs: tropical, vedic_rasi, fagan_bradley. Anchored to a season or a traditional ayanamsa.
  • Unequal — 13 signs including Ophiuchus: sidereal_iau, sidereal_true. Sign widths follow the real size and position of the constellations along the ecliptic.
Pick by what your users expect: an equal-sign wheel when they already think in a familiar system, sidereal_iau for the IAU constellation map, or sidereal_true — GEOMETRY’s recommended default — when you want the wheel that tracks the actual sky most closely.

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Why the degrees differ

Each wheel assigns the Sun (and other bodies) to a sign by ecliptic longitude. The degree tables later on this page are the sign boundaries GEOMETRY uses, published in one shared tropical-longitude frame so you can compare them side by side. Same calendar date → same Sun longitude → different named signs when the cuts differ. That is the whole point of returning five wheels. Membership rule: longitude λ is in a sign when start ≤ λ < end, with wrap-through 0° for Pisces on the sidereal equal wheels and IAU (end < start). These boundaries are standard astronomical and traditional reference frames unified in our catalog — not a secret recipe.

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Different wheel, different sign — by design

If a newspaper or app says “Pisces” and astro_wheels.sidereal_true.sign_name says something else (or Ophiuchus), you are reading two different systems — not catching a GEOMETRY bug. Each wheel cuts the zodiac in its own place, so one date can carry different sign names across the five. Before filing anything, confirm which system you’re comparing:
  1. Which wheel does your source use — tropical, Vedic, Fagan-Bradley, IAU, or true sidereal?
  2. Open the matching key under astro_wheels in the raw JSON and read its sign_name.
  3. Optionally compare the Sun’s tropical longitude for that date to the degree tables below.
  4. For sky dates (moon / season / retro), also read When it covers → Calendar boundaries — a GMT day vs a local almanac is a separate kind of off-by-one.

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Degree tables

Wheel order in the tables follows how Aries is placed in the shared tropical-longitude frame — equal 30° wheels first, then unequal IAU and true sidereal. Jump to a table:
  1. tropical
  2. vedic_rasi
  3. fagan_bradley
  4. sidereal_iau
  5. sidereal_true

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tropical (12)

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vedic_rasi (12)

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fagan_bradley (12)

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sidereal_iau (13)

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sidereal_true (13) — preferred

GEOMETRY’s recommended astrology default when you want a 13-sign true-sidereal reading.

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Coverage

All five wheels ship on the published 1900–2100 focus window. See When it covers.