Nepali Date Modern

A modern, TypeScript-based Nepali date library for Bikram Sambat (B.S.) and Gregorian calendar (A.D.) conversions with comprehensive features.

Note: This is a modernized fork of the original nepali-date package by Ranjan Shrestha. This version includes TypeScript support, enhanced features, and improved maintainability.

Features

• ✅ TypeScript Support - Full TypeScript support with type definitions
• ✅ Extended Date Range - Support for years 2000-2100 BS
• ✅ Accurate Conversions - Precise Bikram Sambat ↔ Gregorian conversions
• ✅ Holiday Detection - Built-in Nepali holiday detection
• ✅ Rich Formatting - Extensive date formatting options in English and Nepali
• ✅ Date Manipulation - Add/subtract days, months, years
• ✅ Date Comparison - Compare dates, calculate differences
• ✅ Leap Year Support - Proper handling of leap years
• ✅ Validation - Comprehensive input validation
• ✅ Modern Build - ES modules, CommonJS, and UMD support

Installation

npm install nepali-date-modern
# or
yarn add nepali-date-modern

Quick Start

import { NepaliDate } from 'nepali-date-modern';

// Create from Nepali date string
const date1 = new NepaliDate('2075-03-22');
console.log(date1.toString()); // "2075/3/22"

// Create from English date
const date2 = new NepaliDate(new Date('2018-07-06'));
console.log(date2.getYear()); // 2075

// Create from components
const date3 = new NepaliDate(2075, 2, 22); // year, month (0-11), day
console.log(date3.getMonth()); // 2 (March)

// Format dates
console.log(date1.format('YYYY-MM-DD')); // "2075-03-22"
console.log(date1.format('yyyy-mm-dd')); // "२०७५-०३-२२"
console.log(date1.format('MMMM D, YYYY')); // "Chaitra 22, 2075"

API Reference

Constructor

new NepaliDate()                    // Current date
new NepaliDate('2075-03-22')       // From Nepali date string
new NepaliDate(new Date())          // From English Date object
new NepaliDate(2075, 2, 22)        // From year, month, day
new NepaliDate(timestamp)           // From timestamp
new NepaliDate(otherNepaliDate)     // Clone existing date

Date Conversion

const nepaliDate = new NepaliDate('2075-03-22');

// Get English date
const englishDate = nepaliDate.getEnglishDate();
console.log(englishDate.toDateString()); // "Fri Jul 06 2018"

// Get timestamp
const timestamp = nepaliDate.getTime();

Date Components

const date = new NepaliDate('2075-03-22');

console.log(date.getYear());    // 2075
console.log(date.getMonth());   // 2 (March, 0-based)
console.log(date.getDate());    // 22
console.log(date.getDay());     // 5 (Friday, 0-based)
console.log(date.getHours());   // Current hour
console.log(date.getMinutes()); // Current minute
console.log(date.getSeconds()); // Current second

Date Manipulation

const date = new NepaliDate('2075-03-22');

// Add/subtract days
const tomorrow = date.addDays(1);
const yesterday = date.addDays(-1);

// Add/subtract months
const nextMonth = date.addMonths(1);
const prevMonth = date.addMonths(-1);

// Add/subtract years
const nextYear = date.addYears(1);
const prevYear = date.addYears(-1);

// Set components
date.setYear(2076);
date.setMonth(4);  // May (0-based)
date.setDate(15);

Date Comparison

const date1 = new NepaliDate('2075-03-22');
const date2 = new NepaliDate('2075-03-23');

console.log(date1.isBefore(date2));  // true
console.log(date2.isAfter(date1));   // true
console.log(date1.equals(date2));    // false

// Calculate difference in days
const diff = date2.diffInDays(date1); // 1

Formatting

The library supports extensive formatting options:

Year Formats

• YYYY - 4 digit year (2075)
• yyyy - 4 digit year in Nepali (२०७५)
• YYY - 3 digit year (075)
• yyy - 3 digit year in Nepali (०७५)
• YY - 2 digit year (75)
• yy - 2 digit year in Nepali (७५)

Month Formats

• M - month number (1-12)
• m - month number in Nepali (१-१२)
• MM - month with zero padding (01-12)
• mm - month in Nepali with zero padding (०१-१२)
• MMM - short month name (Bai, Jes, Asa, etc.)
• mmm - short month name in Nepali (बै, जे, अ, etc.)
• MMMM - full month name (Baisakh, Jestha, etc.)
• mmmm - full month name in Nepali (बैसाख, जेष्ठ, etc.)

Day Formats

• D - day of month (1-31)
• d - day of month in Nepali (१-३१)
• DD - day with zero padding (01-31)
• dd - day in Nepali with zero padding (०१-३१)
• DDD - weekday short (Sun, Mon, etc.)
• ddd - weekday short in Nepali (आइत, सोम, etc.)
• DDDD - weekday full (Sunday, Monday, etc.)
• dddd - weekday full in Nepali (आइतबार, सोमबार, etc.)

Examples

const date = new NepaliDate('2075-03-22');

console.log(date.format('YYYY-MM-DD'));           // "2075-03-22"
console.log(date.format('yyyy-mm-dd'));           // "२०७५-०३-२२"
console.log(date.format('MMMM D, YYYY'));         // "Chaitra 22, 2075"
console.log(date.format('mmmm d, yyyy'));         // "चैत्र २२, २०७५"
console.log(date.format('DDDD, MMMM D'));         // "Friday, Chaitra 22"
console.log(date.format('dddd, mmmm d'));         // "शुक्रबार, चैत्र २२"
console.log(date.format('"Today is" DDDD'));      // "Today is Friday"

Holiday Detection

const date = new NepaliDate('2075-01-01');

// Check if date is a holiday
if (date.isHoliday()) {
  console.log('It\'s a holiday!');
}

// Get holiday details
const holidays = date.getHolidays();
holidays.forEach(holiday => {
  console.log(`${holiday.name} (${holiday.nameNepali})`);
  console.log(`Type: ${holiday.type}`);
});

Leap Year Support

const date = new NepaliDate('2076-01-01');
console.log(date.isLeapYear()); // true

const nonLeapDate = new NepaliDate('2075-01-01');
console.log(nonLeapDate.isLeapYear()); // false

Static Methods

// Create from timestamp
const date1 = NepaliDate.fromTimestamp(Date.now());

// Create from English date string
const date2 = NepaliDate.fromEnglishDate('2018-07-06');

// Get current date
const now = NepaliDate.now();

// Get supported date range
const minDate = NepaliDate.minimum();
const maxDate = NepaliDate.maximum();

Validation

The library includes comprehensive validation:

// Valid dates
new NepaliDate('2075-03-22');  // ✅
new NepaliDate('2075/03/22');  // ✅
new NepaliDate('2075.03.22');  // ✅

// Invalid dates (will throw errors)
new NepaliDate('1999-01-01');  // ❌ Year out of range
new NepaliDate('2101-01-01');  // ❌ Year out of range
new NepaliDate('2075-13-01');  // ❌ Invalid month
new NepaliDate('2075-03-32');  // ❌ Invalid day
new NepaliDate('invalid');      // ❌ Invalid format

Supported Date Range

• Nepali Years: 2000 BS to 2100 BS
• Gregorian Years: 1943 AD to 2043 AD

Build Outputs

The library is built with multiple formats:

• CommonJS: dist/index.js
• ES Modules: dist/index.esm.js
• TypeScript Definitions: dist/index.d.ts

Development

# Install dependencies
npm install

# Run tests
npm test

# Run tests in watch mode
npm run test:watch

# Lint code
npm run lint

# Build library
npm run build

# Development mode (build + test)
npm run dev

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Run tests and linting
6. Submit a pull request

License

MIT License - see LICENSE file for details.

Changelog

v0.2.0 - Modernized Fork

• ✨ TypeScript Support - Full TypeScript rewrite with type definitions
• ✨ Extended Date Range - Support for years 2000-2100 BS
• ✨ Holiday Detection - Built-in Nepali holiday detection
• ✨ Rich Formatting - Enhanced formatting options in English and Nepali
• ✨ Date Manipulation - Add/subtract days, months, years
• ✨ Date Comparison - Compare dates, calculate differences
• ✨ Modern Build - ES modules, CommonJS, and UMD support
• 🐛 Bug Fixes - Fixed date calculation issues
• 📚 Documentation - Comprehensive API documentation
• 🔄 Fork - Modernized version of the original nepali-date package

v0.1.3 (Original Package)

• Initial release with basic functionality by Ranjan Shrestha