vedic_panchanga_dart

pub package License: AGPL v3

A comprehensive Dart port of PyJHora for Vedic astrology panchanga calculations. Provides accurate calculations for traditional Hindu calendar elements and planetary positions using the Swiss Ephemeris.

Features

✨ Complete Panchanga Calculations

  • 🌅 Sunrise, sunset, moonrise, moonset
  • 🌙 Tithi (lunar day) - all 30 tithis
  • ⭐ Nakshatra (lunar mansion) with pada - all 27 nakshatras
  • 🔄 Yoga - all 27 yogas
  • 📆 Karana - all 11 karanas
  • ♈ Moon's Rasi (zodiac sign)

🔭 Astronomical Features

  • Planetary positions (Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu, Ketu)
  • Sidereal longitude calculations
  • Retrograde planet detection
  • Multiple ayanamsa modes (LAHIRI, KP, RAMAN, TRUE_CITRA, etc.)

🎯 High Precision

  • Based on Swiss Ephemeris for accurate planetary positions
  • Supports all major ayanamsa systems
  • Inverse Lagrange interpolation for precise event timings

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  vedic_panchanga_dart: ^0.1.0

Then run:

dart pub get

Or for Flutter projects:

flutter pub get

Usage

Basic Example

import 'package:vedic_panchanga_dart/vedic_panchanga_dart.dart';

void main() {
  // Initialize the service with desired ayanamsa mode
  PanchangaService.initialize(ayanamsaMode: 'LAHIRI');

  // Create a place (name, latitude, longitude, timezone in hours)
  final chennai = Place('Chennai', 13.0827, 80.2707, 5.5);

  // Calculate panchanga for a specific date
  final date = DateTime(2024, 10, 28);
  final panchanga = PanchangaService.calculatePanchanga(date, chennai);

  // Print the complete panchanga
  print(panchanga);
}

Output Example

Panchanga for 2024-10-28 at Chennai
============================================
Weekday: Monday
Sunrise: 06:10:23 AM
Sunset: 05:52:14 PM
Day Length: 11.70 hours
Night Length: 12.30 hours

Tithi: Saptami (05:30 - 18:45)
Nakshatra: Rohini Pada 3 (04:20 - 19:30)
Yoga: Vyaghata (ends at 15:22)
Karana: Bava (ends at 18:45)
Rasi: Taurus (ends at 20:15)

Moonrise: 11:30:45 AM
Moonset: 10:45:22 PM
============================================

Calculate Individual Elements

import 'package:vedic_panchanga_dart/vedic_panchanga_dart.dart';

void main() {
  PanchangaService.initialize();
  
  final place = Place('Mumbai', 19.0760, 72.8777, 5.5);
  final jd = PanchangaUtils.gregorianToJd(2024, 10, 28);

  // Calculate sunrise/sunset
  final sunrise = PanchangaService.sunrise(jd, place);
  print('Sunrise: ${sunrise['timeString']}');

  // Calculate tithi
  final tithi = PanchangaService.tithi(jd, place);
  print('Tithi: ${tithi.name}');

  // Calculate nakshatra
  final nakshatra = PanchangaService.nakshatra(jd, place);
  print('Nakshatra: ${nakshatra.name} Pada ${nakshatra.pada}');

  // Get planet positions
  final planets = PanchangaService.planetPositions(jd, place);
  for (final planet in planets) {
    print(planet);
  }
}

Different Ayanamsa Modes

// Use Krishnamurti Paddhati (KP) system
PanchangaService.initialize(ayanamsaMode: 'KP');

// Use Raman ayanamsa
PanchangaService.initialize(ayanamsaMode: 'RAMAN');

// Use True Citra ayanamsa
PanchangaService.initialize(ayanamsaMode: 'TRUE_CITRA');

Available ayanamsa modes:

  • LAHIRI (default) - Most commonly used in India
  • KP - Krishnamurti Paddhati
  • RAMAN - B.V. Raman's ayanamsa
  • TRUE_CITRA - True Chitra Paksha ayanamsa
  • TRUE_REVATI - True Revati ayanamsa
  • ARYABHATA - Aryabhata's ayanamsa
  • SURYASIDDHANTA - Surya Siddhanta ayanamsa
  • And more...

JSON Export

final panchanga = PanchangaService.calculatePanchanga(date, place);
final json = panchanga.toJson();
print(json);

API Reference

PanchangaService

Main service class for all calculations.

Methods:

  • initialize({String ayanamsaMode}) - Initialize with ayanamsa mode
  • calculatePanchanga(DateTime date, Place place) - Get complete panchanga
  • sunrise(double jd, Place place) - Calculate sunrise
  • sunset(double jd, Place place) - Calculate sunset
  • moonrise(double jd, Place place) - Calculate moonrise
  • moonset(double jd, Place place) - Calculate moonset
  • tithi(double jd, Place place) - Calculate tithi
  • nakshatra(double jd, Place place) - Calculate nakshatra
  • yoga(double jd, Place place) - Calculate yoga
  • karana(double jd, Place place) - Calculate karana
  • moonRasi(double jd, Place place) - Calculate moon's rasi
  • planetPositions(double jd, Place place) - Get all planet positions
  • siderealLongitude(double jdUtc, int planet) - Get planet's sidereal longitude

PanchangaUtils

Utility functions for conversions and calculations.

Methods:

  • gregorianToJd(year, month, day, {hour, minute, second}) - Convert to Julian Day
  • jdToGregorian(jd) - Convert from Julian Day
  • norm360(degrees) - Normalize angle to 0-360
  • toDms(decimalHours, {asString}) - Convert to hours:minutes:seconds
  • inverseLagrange(x, y, yTarget) - Inverse Lagrange interpolation

Models

Place

  • Represents geographical location with timezone

PanchangaData

  • Complete panchanga information for a day

TithiInfo

  • Tithi number, name, start/end times

NakshatraInfo

  • Nakshatra number, name, pada, start/end times

YogaInfo

  • Yoga number, name, end time

KaranaInfo

  • Karana number, name, end time

RasiInfo

  • Rasi number, name, end time

PlanetPosition

  • Planet longitude, latitude, speed, retrograde status, rasi

Background

This package is a Dart port of the excellent PyJHora Python library by @naturalstupid. PyJHora itself is based on algorithms from PVR Narasimha Rao's JHora software, a widely respected tool in Vedic astrology.

Porting Notes

The port maintains the same calculation accuracy as PyJHora by using:

  • Swiss Ephemeris (via the sweph package)
  • Same interpolation algorithms
  • Same ayanamsa modes and constants

Limitations

  • Requires Swiss Ephemeris data files (handled automatically by the sweph package)
  • Currently supports core panchanga features
  • Advanced features (dashas, divisional charts, yogas) planned for future releases

Roadmap

  • Vimsottari Dasha calculations
  • Divisional charts (D-1 to D-144)
  • Advanced yoga detection
  • Ashtakavarga calculations
  • Planetary aspects and relationships
  • Support for other calendar systems

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0) - see the LICENSE file for details.

This license is chosen to match the original PyJHora license. The AGPL-3.0 ensures that:

  • The source code must remain open
  • Any modifications must also be open-sourced
  • Network use counts as distribution (important for web applications)

Credits

  • PyJHora by @naturalstupid - Original Python implementation
  • PVR Narasimha Rao - JHora software and algorithms
  • Swiss Ephemeris - Astronomical calculations
  • sweph package - Dart bindings for Swiss Ephemeris

References

Support

If you find this package useful, please give it a ⭐ on GitHub and a 👍 on pub.dev!

For bugs and feature requests, please file an issue on GitHub.

Libraries

vedic_panchanga_dart
A Dart port of PyJHora for Vedic astrology panchanga calculations.