Nepali Date Engine (nepali-date-engine)

A robust, standalone, and highly accurate Nepali Date (Bikram Sambat) and Panchang library for Node.js and the browser.

Features

• Zero Dependencies: Pure TypeScript implementation. No external runtime calls.
• Extended Range: Accurate conversion from 1970 BS to 2090 BS (1913 AD - 2033 AD).
• Full Panchang: High-precision astronomical calculations for:
  • Tithi (Lunar Day)
  • Nakshatra (Lunar Mansion)
  • Yoga
  • Karana
  • Sunrise / Sunset (Approximate)
• High Accuracy:
  • Validated against 100+ years of calendar data.
  • Smart Corrections: Includes a manual override system to align Tithis with official government calendars when astronomical calculations differ.
• Rich Holiday Database: Built-in database of Nepali holidays from 1970 BS to 2074 BS.
• Localization: Full support for Nepali (Devanagari) digits and names.

Installation

npm install nepali-date-engine

🚀 HTTP API & Self-Hosting

This engine also comes with a built-in REST API server (compatible with Vercel).

Quick Start:

# Start the dev server
npm run dev

# Test
curl http://localhost:3000/today

For detailed deployment instructions (NPM, GitHub, Vercel), see DEPLOY.md.

Usage

Basic Conversion

import { getNepaliDate } from 'nepali-date-engine';

const date = new Date('2026-01-21');
const nepali = getNepaliDate(date);

console.log(nepali.bs); 
// { year: 2082, month: 10, day: 8, dayOfWeek: 4, yearNp: '२०८२', ... }

console.log(nepali.tithi);
// { name: 'Chaturthi', paksha: 'Shukla', nakshatra: { ... }, ... }

Checking Holidays

if (nepali.holiday?.isHoliday) {
  console.log(`Today is ${nepali.holiday.name?.en}`);
  // Output: "Today is Sonam Lhosar"
}

API Reference

getNepaliDate(date: Date): NepaliDateDetail

Returns a comprehensive object containing:

• ad: Original JS Date.
• bs: Converted Bikram Sambat date (Year, Month, Day, Weekday).
• tithi: Astronomical details (Tithi, Paksha, Nakshatra, Yoga, Karana).
• holiday: Holiday information if applicable.

adToBs(date: Date): BsDate

Stand-alone function for AD to BS conversion.

bsToAd(bsDate: BsDate): Date

Stand-alone function for BS to AD conversion.

Dataset

This engine uses a merged dataset validated against multiple sources:

• 1970-1999 BS: Sourced from historical calendar archives.
• 2000-2090 BS: Verified against standard conversion libraries.
• Holidays: Includes a bundled, Offline-ready database of holidays spanning 50+ years.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for details on how to get started.

License

This project is licensed under the Apache License 2.0. See the LICENSE file for details.

💖 Sponsors

We love our sponsors! If you'd like to support the project, please check out our Sponsorship Page.

☕ Support

If you find this tool helpful, consider supporting: Support on Ko-fi