ad-to-bs

A lightweight TypeScript library for converting between Gregorian (AD) and Nepali (BS/Bikram Sambat) calendars.

Features

• ✅ Convert Gregorian dates to Nepali calendar
• ✅ Convert Nepali dates to Gregorian calendar
• ✅ Date validation for both calendars
• ✅ TypeScript support with full type definitions
• ✅ ESM module format
• ✅ Supports date range: 1944–2100 (AD) / 2000–2100 (BS)

Installation

npm install ad-to-bs

Usage

Basic Conversion

import { gregorianToNepali, nepaliToGregorian } from 'ad-to-bs';

// Convert Gregorian to Nepali
const nepaliDate = gregorianToNepali(2023, 10, 17);
console.log(nepaliDate); // { year: 2080, month: 7, day: 1 }

// Convert Nepali to Gregorian
const gregorianDate = nepaliToGregorian(2080, 7, 1);
console.log(gregorianDate); // { year: 2023, month: 10, day: 17 }

Validation

import { validateGregorian, validateNepali } from 'ad-to-bs';

const result = validateGregorian(2023, 10, 17);
if (result.valid) {
  console.log('Valid date');
} else {
  console.log('Error:', result.error);
}

API

gregorianToNepali(year: number, month: number, day: number): CalendarDate

Converts a Gregorian date to Nepali calendar.

Parameters:

• year: Gregorian year (1944–2100)
• month: Month (1–12)
• day: Day of month

Returns: { year, month, day } in Nepali calendar

Throws: Error if date is invalid

nepaliToGregorian(year: number, month: number, day: number): CalendarDate

Converts a Nepali date to Gregorian calendar.

Parameters:

• year: Nepali year (2000–2100)
• month: Month (1–12)
• day: Day of month

Returns: { year, month, day } in Gregorian calendar

Throws: Error if date is invalid

validateGregorian(year: number, month: number, day: number): ValidationResult

Validates a Gregorian date.

Returns: { valid: boolean, error?: string }

validateNepali(year: number, month: number, day: number): ValidationResult

Validates a Nepali date.

Returns: { valid: boolean, error?: string }

Development

Install dependencies

bun install

Build

bun run build

Run tests

bun run test

Run tests once

bun run test:run

License

MIT