Localization

@thaparoyal/calendar-core provides full support for English and Nepali (Devanagari) display, including month names, weekday names, numerals, and date formatting.

Locale Option

The locale config option controls the display language across all frameworks:

type Locale = 'en' | 'ne';

Locale	Numerals	Month Names	Weekday Names
`'en'`	1, 2, 3 …	Baisakh, Jestha …	Sun, Mon …
`'ne'`	१, २, ३ …	बैशाख, जेठ …	आइत, सोम …

Using in Config

The locale is part of CalendarConfig and works across all frameworks:

// Vanilla JS
render('#cal', {
  config: { calendarType: 'BS', locale: 'ne' },
});

// React
<Calendar.Root config={{ calendarType: 'BS', locale: 'ne' }}>

// Vue
const { weeks } = useCalendar({
  config: { calendarType: 'BS', locale: 'ne' },
});

// Svelte
const { weeks } = createCalendar({
  config: { calendarType: 'BS', locale: 'ne' },
});

When using locale: 'ne', add data-locale="ne" on the calendar wrapper to enable the Devanagari font styling:

<div class="trc-calendar" data-theme="default" data-locale="ne">

Nepali Numerals

Convert between Arabic (0-9) and Devanagari numerals:

import { toNepaliNumeral, fromNepaliNumeral, NEPALI_DIGITS } from '@thaparoyal/calendar-core';

toNepaliNumeral(2082);    // '२०८२'
toNepaliNumeral(15);      // '१५'

fromNepaliNumeral('२०८२'); // 2082
fromNepaliNumeral('१५');   // 15

// Individual digit mapping
NEPALI_DIGITS;
// ['०', '१', '२', '३', '४', '५', '६', '७', '८', '९']

Month Names

BS Month Names

import {
  BS_MONTHS_EN,
  BS_MONTHS_NP,
  BS_MONTHS_SHORT_EN,
  BS_MONTHS_SHORT_NP,
  getMonthName,
  getMonthShortName,
  getMonthNames,
} from '@thaparoyal/calendar-core';

// Full arrays
BS_MONTHS_EN;
// ['Baisakh', 'Jestha', 'Ashadh', 'Shrawan', 'Bhadra', 'Ashwin',
//  'Kartik', 'Mangsir', 'Poush', 'Magh', 'Falgun', 'Chaitra']

BS_MONTHS_NP;
// ['बैशाख', 'जेठ', 'असार', 'श्रावण', 'भाद्र', 'आश्विन',
//  'कार्तिक', 'मंसिर', 'पौष', 'माघ', 'फाल्गुन', 'चैत्र']

BS_MONTHS_SHORT_EN;
// ['Bai', 'Jes', 'Ash', 'Shr', 'Bhd', 'Asw',
//  'Kar', 'Man', 'Pou', 'Mag', 'Fal', 'Cha']

// Get by index (1-based month number)
getMonthName(1, 'BS', 'en');      // 'Baisakh'
getMonthName(1, 'BS', 'ne');      // 'बैशाख'
getMonthName(1, 'AD', 'en');      // 'January'

getMonthShortName(1, 'BS', 'en'); // 'Bai'

// Get all month names for a calendar type
getMonthNames('BS', 'en');        // ['Baisakh', 'Jestha', ...]
getMonthNames('AD', 'en');        // ['January', 'February', ...]

Weekday Names

import {
  WEEKDAYS_EN,
  WEEKDAYS_NP,
  WEEKDAYS_SHORT_EN,
  WEEKDAYS_SHORT_NP,
  WEEKDAYS_MIN_EN,
  WEEKDAYS_MIN_NP,
  getWeekdayName,
  getWeekdayShortName,
  getWeekdayMinName,
  getWeekdayNames,
  getWeekdayShortNames,
  getWeekdayMinNames,
} from '@thaparoyal/calendar-core';

// Full names (index 0 = Sunday)
WEEKDAYS_EN;     // ['Sunday', 'Monday', 'Tuesday', ...]
WEEKDAYS_NP;     // ['आइतबार', 'सोमबार', 'मंगलबार', ...]

// Short names
WEEKDAYS_SHORT_EN;  // ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat']
WEEKDAYS_SHORT_NP;  // ['आइत', 'सोम', 'मंगल', 'बुध', 'बिही', 'शुक्र', 'शनि']

// Minimal names (calendar grid headers)
WEEKDAYS_MIN_EN;    // ['S', 'M', 'T', 'W', 'T', 'F', 'S']
WEEKDAYS_MIN_NP;    // ['आ', 'सो', 'मं', 'बु', 'बि', 'शु', 'श']

// By index (0 = Sunday)
getWeekdayName(0, 'en');      // 'Sunday'
getWeekdayName(0, 'ne');      // 'आइतबार'
getWeekdayShortName(1, 'en'); // 'Mon'
getWeekdayMinName(2, 'ne');   // 'मं'

// Get all names for a locale
getWeekdayNames('en');        // ['Sunday', 'Monday', ...]
getWeekdayShortNames('ne');   // ['आइत', 'सोम', ...]
getWeekdayMinNames('en');     // ['S', 'M', 'T', 'W', 'T', 'F', 'S']

Date Formatting

formatDate

Format a CalendarDate using token-based patterns:

import { formatDate } from '@thaparoyal/calendar-core';

const date = { year: 2082, month: 11, day: 14, calendarType: 'BS' as const };

formatDate(date, 'YYYY-MM-DD');         // '2082-11-14'
formatDate(date, 'YYYY-MM-DD', 'ne');   // '२०८२-११-१४'
formatDate(date, 'MMMM DD, YYYY');      // 'Falgun 14, 2082'
formatDate(date, 'MMMM DD, YYYY', 'ne'); // 'फाल्गुन १४, २०८२'
formatDate(date, 'MMM D');              // 'Fal 14'
formatDate(date, 'dddd, MMMM D, YYYY'); // 'Friday, Falgun 14, 2082'

Format Tokens

Token	Output	Example
`YYYY`	4-digit year	`2082`
`YY`	2-digit year	`82`
`MMMM`	Full month name	`Falgun`
`MMM`	Short month name	`Fal`
`MM`	2-digit month	`11`
`M`	Month number	`11`
`DD`	2-digit day	`14`
`D`	Day number	`14`
`dddd`	Full weekday name	`Friday`
`ddd`	Short weekday name	`Fri`
`d`	Day of week (0-6)	`5`

All tokens are locale-aware. With locale: 'ne', numeric tokens output Nepali numerals and name tokens output Nepali text.

parseDate

Parse a date string into a CalendarDate:

import { parseDate } from '@thaparoyal/calendar-core';

parseDate('2082-11-14', 'BS');
// { year: 2082, month: 11, day: 14, calendarType: 'BS' }

parseDate('2026/02/27', 'AD');
// { year: 2026, month: 2, day: 27, calendarType: 'AD' }

parseDate('invalid', 'BS');
// null

Supported input formats: YYYY-MM-DD and YYYY/MM/DD.

formatMonthYear

Convenience function for calendar titles:

import { formatMonthYear } from '@thaparoyal/calendar-core';

formatMonthYear(2082, 11, 'BS', 'en');  // 'Falgun 2082'
formatMonthYear(2082, 11, 'BS', 'ne');  // 'फाल्गुन २०८२'
formatMonthYear(2026, 2, 'AD', 'en');   // 'February 2026'

formatDateRange

Format a date range:

import { formatDateRange } from '@thaparoyal/calendar-core';

const start = { year: 2082, month: 11, day: 1, calendarType: 'BS' as const };
const end = { year: 2082, month: 11, day: 15, calendarType: 'BS' as const };

formatDateRange(start, end, 'YYYY-MM-DD');
// '2082-11-01 - 2082-11-15'

formatDateRange(start, end, 'MMM D', 'ne');
// 'फा १ - फा १५'

Day and Year Formatting

Locale-aware formatting for individual numbers:

import { formatDay, formatYear } from '@thaparoyal/calendar-core';

formatDay(15, 'en');    // '15'
formatDay(15, 'ne');    // '१५'

formatYear(2082, 'en'); // '2082'
formatYear(2082, 'ne'); // '२०८२'

UI Text Translations

Pre-defined translations for common UI strings:

import { TODAY_TEXT, CLEAR_TEXT, SELECT_DATE_TEXT, PREV_MONTH_TEXT, NEXT_MONTH_TEXT } from '@thaparoyal/calendar-core';

TODAY_TEXT.en;         // 'Today'
TODAY_TEXT.ne;         // 'आज'

CLEAR_TEXT.en;         // 'Clear'
CLEAR_TEXT.ne;         // 'मेटाउनुहोस्'

SELECT_DATE_TEXT.en;   // 'Select date'
SELECT_DATE_TEXT.ne;   // 'मिति छान्नुहोस्'

PREV_MONTH_TEXT.en;    // 'Previous month'
PREV_MONTH_TEXT.ne;    // 'अघिल्लो महिना'

NEXT_MONTH_TEXT.en;    // 'Next month'
NEXT_MONTH_TEXT.ne;    // 'अर्को महिना'

API Reference

Function / Constant	Description
`toNepaliNumeral(num)`	Convert number to Nepali digits
`fromNepaliNumeral(str)`	Convert Nepali digit string to number
`NEPALI_DIGITS`	Array of 10 Nepali digits
`getMonthName(month, type, locale)`	Full month name
`getMonthShortName(month, type, locale)`	Short month name
`getMonthNames(type, locale)`	All month names
`getWeekdayName(dayOfWeek, locale)`	Full weekday name
`getWeekdayShortName(dayOfWeek, locale)`	Short weekday name
`getWeekdayMinName(dayOfWeek, locale)`	Minimal weekday label
`getWeekdayNames(locale)`	All weekday names
`getWeekdayShortNames(locale)`	All short weekday names
`getWeekdayMinNames(locale)`	All minimal weekday names
`formatDate(date, format, locale)`	Token-based date formatting
`parseDate(str, calendarType)`	Parse date string
`formatMonthYear(year, month, type, locale)`	Month + year string
`formatDateRange(start, end, format, locale)`	Formatted range
`formatDay(day, locale)`	Locale-aware day number
`formatYear(year, locale)`	Locale-aware year number
`BS_MONTHS_EN`	BS month names in English
`BS_MONTHS_NP`	BS month names in Nepali
`BS_MONTHS_SHORT_EN`	Short BS month names (English)
`BS_MONTHS_SHORT_NP`	Short BS month names (Nepali)
`WEEKDAYS_EN`	Full weekday names (English)
`WEEKDAYS_NP`	Full weekday names (Nepali)
`WEEKDAYS_SHORT_EN`	Short weekday names (English)
`WEEKDAYS_SHORT_NP`	Short weekday names (Nepali)
`WEEKDAYS_MIN_EN`	Minimal weekday names (English)
`WEEKDAYS_MIN_NP`	Minimal weekday names (Nepali)