virnavi_islamic_calculator

A Flutter package for Islamic calculations — prayer times, Hijri calendar, Ramadan & Hajj detection, and Zakat.

Features

• Prayer times with 20+ built-in calculation methods and per-country defaults
• Madhab selection — Hanafi or Shafi/Maliki/Hanbali Asr shadow factor
• Sunnah prayers — Tahajjud, Duha, Awwabin, Witr
• Hijri calendar converter (tabular 30-year cycle)
• Ramadan detection with Imsak time
• Hajj season detection — Arafah, Eid al-Adha, Tashreeq days
• Zakat calculator — gold/silver nisab, gross/net wealth, 2.5% computation
• JSON serialization for caching timetables
• Local time I/O — pass a local DateTime to get local times back

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Getting Started

dependencies:
  virnavi_islamic_calculator: ^0.0.2

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Usage

Prayer times — country defaults

import 'package:virnavi_islamic_calculator/virnavi_islamic_calculator.dart';

// Load the recommended method for a country
final config = await CountryConfig.getByCountryCode('bd'); // Bangladesh
var method = await SalahCalculationMethod.getCalculationMethod(
    config.method.defaultValue);
method = method.copyWith(madhab: config.asrMethod.defaultValue);

// Calculate for today (local time in, local time out)
final times = await SalahTimes.calculate(
  date: DateTime.now(),
  latitude: 23.7771,
  longitude: 90.3994,
  method: method,
);

print(times.fajr.start);    // local DateTime
print(times.maghrib.start); // local DateTime
print(times.imsak);         // 10 min before Fajr (Ramadan use)

Choosing a specific method

final config = await SalahTimeConfig.get();
// config.methods — full list of all available methods

final method = await SalahCalculationMethod.getCalculationMethod('karachi');

Applying custom minute adjustments

final adjusted = method.copyWith(
  adjustments: Adjustments(fajr: 2, isha: -1),
);

Hijri calendar

final hijri = HijriDate.fromGregorian(DateTime.now());
print(hijri);           // e.g. "16 Ramadan 1447 AH"
print(hijri.isRamadan); // true/false
print(hijri.monthName); // "Ramadan"

Ramadan

final times = await SalahTimes.calculate(...);
if (times.isRamadan) {
  print('Imsak: ${times.imsak}');          // 10 min before Fajr
  print('Suhoor ends: ${times.fajr.start}');
  print('Iftar: ${times.maghrib.start}');
}

Hajj season

if (times.isHajjSeason) {
  if (times.isArafah)    print('Day of Arafah — fast today!');
  if (times.isEidAlAdha) print('Eid al-Adha Mubarak!');
}

Zakat calculator

final calc = ZakatCalculator(
  goldPricePerGram: 8000,   // your local currency per gram
  silverPricePerGram: 100,
  nisabStandard: NisabStandard.gold, // or NisabStandard.silver
  cash: 500000,
  goldValue: 200000,
  investments: 100000,
  debts: 50000,
);

final result = calc.calculate();
print('Net wealth: ${result.netWealth}');
print('Nisab: ${result.applicableNisab}');
print('Zakat due: ${result.zakatDue}');    // 0 if below nisab
print('Is zakat due: ${result.isZakatDue}');

IslamicCalculatorService (unified API)

A single service class that wraps all package functionality in one place:

const service = IslamicCalculatorService();

// Prayer times
final method = await service.getCalculationMethod('karachi');
final times  = await service.getSalahTimes(
  date: DateTime.now(), latitude: 23.7771, longitude: 90.3994, method: method,
);

// Hijri date
final hijri = service.toHijriDate(DateTime.now());

// Zakat
final result = service.calculateZakat(
  goldPricePerGram: 8000, silverPricePerGram: 100, cash: 500000, debts: 50000,
);

// Country defaults
final country = await service.getCountryConfig('BD');

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Calculation Methods

ID	Name
karachi	University of Islamic Sciences, Karachi
isna	Islamic Society of North America
mwl	Muslim World League
makkah	Umm Al-Qura University, Makkah
egypt	Egyptian General Authority of Survey
tehran	Institute of Geophysics, University of Tehran
gulf	Gulf Region
kuwait	Kuwait
qatar	Qatar
singapore	Majlis Ugama Islam Singapura
france	Union des organisations islamiques de France
turkey	Diyanet İşleri Başkanlığı
russia	Spiritual Administration of Muslims of Russia
dubai	Dubai
morocco	Morocco
...and more	See SalahTimeConfig.get() for the full list

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Accuracy

Results are verified against IslamicFinder for Dhaka (Karachi method, Hanafi madhab):

Prayer	This package	IslamicFinder	Diff
Fajr	05:01	05:03	2 min
Dhuhr	12:11	12:11	exact
Maghrib	18:04	18:03	1 min
Isha	19:18	19:18	exact

Asr difference is expected when comparing different madhabs (Hanafi vs Shafi).

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Contributors

Name	Role
Mohammed Shakib (@shakib1989)	Main Library Development

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Additional Information

• Issues & contributions: open an issue or PR on GitHub
• Prayer time calculations use standard solar angle formulas (suncalc-based)
• The Hijri calendar uses the tabular 30-year cycle; results may differ by ±1 day from moon-sighting-based calendars
• Zakat nisab values follow the standard scholarly consensus (85 g gold / 595 g silver)