Panchangam (Wasm)

High-Precision Vedic Astrology & Calendar Library

Powered by Swiss Ephemeris | Compiled to WebAssembly | Built for the Edge

🌟 Why Panchangam?

Most Vedic astrology libraries rely on static lookup tables or simplified algorithms that trade accuracy for speed. Panchangam bridges the gap between ancient Vedic requirements and modern astronomical precision.

1. Astronomical Precision ("Drik Ganita"): We wrap the industry-standard Swiss Ephemeris (used by NASA/JPL) to calculate planetary positions to millisecond precision. No approximations.
2. The "Udaya Tithi" Standard: In Vedic traditions, the day doesn't start at midnight; it starts at Sunrise. We calculate exact local sunrise times (taking atmospheric refraction and altitude into account) to determine the correct Tithi, Nakshatra, and Yoga for any location on Earth.
3. Wasm-First Performance: Written in Rust and compiled to WebAssembly, this library runs with near-native performance in Node.js, Deno, and Cloudflare Workers. It's designed for serverless scalability.

✨ Features

• Swiss Ephemeris v2.10.03: The gold standard for planetary calculations.
• Vedic Calendar (Panchang):
  • Tithi: Lunar day (1-30) with end times calculated via iterative binary search.
  • Nakshatra: 27 Lunar mansions.
  • Yoga: 27 Luni-solar combinations.
  • Karana: 11 Half-Tithis.
  • Vara: Weekday based on sunrise-to-sunrise logic.
• Advanced Astronomy:
  • True Ayanamsa: Support for Lahiri (Chitrapaksha), Raman, Krishnamurti, and more.
  • Planetary War (Graha Yuddha): Detects when planets are dangerously close (< 1°).
  • Muhurat: Real-time calculation of Rahu Kalam, Yamaganda, and Gulika (8-part day division).

🚀 Usage

Installation

This project is currently distributed as a source crate. You verify and build the Wasm bindings locally.

Prerequisites:

• Rust (stable)
• Deno (v1.37+)

One-Step Build:

deno task build

This generates:

• ./lib/panchangam.js: The ESM entry point.
• ./lib/panchangam.wasm: The compiled Wasm binary.
• ./lib/panchangam.d.ts: Fully typed TypeScript definitions.

Quick Start

import { calculate_daily_panchang, Location } from "./lib/panchangam.js";

// 1. Define Location: Bangalore (12.97 N, 77.59 E, 920m altitude)
const bangalore = new Location(12.9716, 77.5946, 920.0);

// 2. Calculate for January 5, 2026
// params: (year, month, day, location, ayanamsha_mode)
// mode 1 = Lahiri (Chitrapaksha)
const result = calculate_daily_panchang(2026, 1, 5, bangalore, 1);

// 3. Output Results
console.log(`Date: ${result.date}`);
console.log(`Sunrise: ${new Date(result.sunrise).toLocaleTimeString()}`);
console.log(
  `Tithi: ${result.tithi_name} (Ends at ${
    new Date(result.tithi_end_time).toLocaleTimeString()
  })`,
);
console.log(`Nakshatra: ${result.nakshatra_name}`);

Advanced: Planetary War

import { check_graha_yuddha, swe_julday } from "./lib/panchangam.js";

const jd = swe_julday(2026, 1, 6, 12.0, 1); // Jan 6, 2026
const conflicts = check_graha_yuddha(jd, 1);

if (conflicts.length > 0) {
  conflicts.forEach((war) => {
    console.warn(
      `⚔️ PLANETARY WAR: ${war.planet1_name} vs ${war.planet2_name}`,
    );
    console.log(
      `Winner: ${
        war.winner_id === war.planet1_id ? war.planet1_name : war.planet2_name
      }`,
    );
  });
}

🛠️ Development

Project Structure

• src/lib.rs: Wasm entry point (exposes functions to JS).
• src/vedic/: Core Vedic algorithms (Tithi, Nakshatra, etc.).
• src/astronomy/: Swiss Ephemeris wrappers and solvers.
• scripts/build_npm.ts: Build script to generate NPM/Deno package.

Testing

Run the Deno-based verification suite:

deno test --allow-read --allow-env

License

MIT