JPL DE440, Lahiri & Vedic charts
Why DE440 matters
Planetary longitudes drive lagna, rashi, nakshatra, and Vimshottari dasha boundaries. Small errors at birth time compound into wrong dasha lords or house placements. We use the JPL DE440 kernel on our dedicated Astro Engine (Rust, Cloud Run) rather than approximations.
DE440 is the successor to DE431/DE440-family kernels used in professional astronomy; for Jyotish we convert tropical positions to sidereal using Lahiri ayanamsa and apply standard house and dasha rules from classical texts.
Computation pipeline
Birth date, time, and place (latitude, longitude, timezone) → UTC instant → JPL DE440 barycentric/geocentric positions → light-time correction → Lahiri sidereal longitude → whole-sign (or configured) houses → Vimshottari dasha tree.
- Birth time
- DE440
- Light-time
- Lahiri
- Houses
- Dasha
Panchang & festival timing pipeline
Festival civil dates and muhurat windows use the same astronomical core as birth charts, but the observance anchor differs: tithi is sampled at local sunrise (or local sunset for Pradosh festivals), then mapped to the civil calendar in the observer's IANA timezone — including daylight saving transitions.
- Coordinates
- Timezone
- Sunrise
- Tithi
- Civil date
- Muhurat
India anchor dates for the Global Hindu Festival Timing Index use Delhi coordinates; each diaspora city recomputes tithi at its own sunrise. Deterministic calculations only — Patrika PDF narrative is AI-generated separately and is not part of this pipeline.
Known limitations: moonrise-anchored vrats (e.g. Karwa Chauth moon sighting), nishita (midnight) festivals such as Maha Shivaratri, and tradition-specific variants (Smarta vs Vaishnava Janmashtami) may differ from local community practice.
Provenance
Fetched from GET /provenance on the Astro Engine. When live fetch fails, we show the last hourly mirror from our database.
Source: live Astro Engine
| Kernel ID | de440 |
|---|---|
| Kernel hash | bf006518b13e30ba8b4b852e025b6dd748960a77b3b61f946547e86558e90587 |
| Ayanamsa | lahiri_swe_zero_epoch_iau1976_v1 |
| Engine version | — |
| Build date | 2026-06-19T14:27:36Z |
As of 2026-08-31T19:54:14.196Z
How we compare
Sprint 27 will publish side-by-side deltas vs Swiss Ephemeris and sample commercial APIs. Until then, per-request engineUsed telemetry tracks in-house, Astro Engine, and fallback paths.
| Source | Status |
|---|---|
| Astro Engine (DE440) | Production path when USE_ASTRO_API_V2=true |
| Swiss Ephemeris (webapp fallback) | Active until flip soak complete |
| Comparison report | Planned — Sprint 27 |