NepaliDate Class

The NepaliDate class is the core of the library, providing a complete API for creating, manipulating, and formatting Nepali (Bikram Sambat) dates.

Import

import { NepaliDate } from "nepali-date-library";

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Constructors

The NepaliDate class supports multiple constructor signatures:

Default Constructor

Creates a NepaliDate for the current date and time.

new NepaliDate();

Example:

const today = new NepaliDate();
console.log(today.toString()); // '2082/10/01'

From JavaScript Date

Creates a NepaliDate from a JavaScript Date object.

new NepaliDate(date: Date)

Parameters:

• date - JavaScript Date object

Example:

const jsDate = new Date("2026-01-14");
const nepaliDate = new NepaliDate(jsDate);
console.log(nepaliDate.toString()); // '2082/10/01'

From NepaliDate

Creates a copy of another NepaliDate instance.

new NepaliDate(date: NepaliDate)

Example:

const original = new NepaliDate();
const copy = new NepaliDate(original);

From Timestamp

Creates a NepaliDate from a Unix timestamp in milliseconds.

new NepaliDate(timestamp: number)

Example:

const nepaliDate = new NepaliDate(Date.now());

From Date String

Creates a NepaliDate from a formatted date string.

new NepaliDate(dateString: string)

Supported formats:

• YYYY-MM-DD (e.g., '2082-10-01')
• YYYY/MM/DD (e.g., '2082/10/01')
• YYYY.MM.DD (e.g., '2082.10.01')

Example:

const date = new NepaliDate("2082-10-15");
console.log(date.getYear()); // 2082
console.log(date.getMonth()); // 9 (0-indexed)
console.log(date.getDate()); // 15

From Components

Creates a NepaliDate with specific year, month, and day values.

new NepaliDate(year: number, month: number, day: number)

Parameters:

• year - Nepali year (e.g., 2082)
• month - Nepali month (0-11, where 0 = Baisakh)
• day - Day of month (1-32)

Month is 0-indexed

The month parameter is 0-indexed: 0 = Baisakh, 1 = Jestha, ..., 11 = Chaitra

Example:

// Magh 15, 2082 (month 9 = Magh since 0-indexed)
const date = new NepaliDate(2082, 9, 15);
console.log(date.format("MMMM DD, YYYY")); // 'Magh 15, 2082'

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Getter Methods

getYear()

Returns the Nepali year.

getYear(): number

Returns: Nepali year (e.g., 2082)

Example:

const date = new NepaliDate(2082, 9, 15);
console.log(date.getYear()); // 2082

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getMonth()

Returns the Nepali month (0-indexed).

getMonth(): number

Returns: Nepali month (0-11, where 0 = Baisakh, 11 = Chaitra)

Example:

const date = new NepaliDate(2082, 9, 15);
console.log(date.getMonth()); // 9 (Magh)

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getDate()

Returns the day of the month.

getDate(): number

Returns: Day of month (1-32)

Example:

const date = new NepaliDate(2082, 9, 15);
console.log(date.getDate()); // 15

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getDay()

Returns the day of the week.

getDay(): number

Returns: Day of week (0-6, where 0 = Sunday, 6 = Saturday)

Example:

const date = new NepaliDate(2082, 9, 15);
console.log(date.getDay()); // 3 (Wednesday)

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getHours()

Returns the hour component.

getHours(): number

Returns: Hour (0-23)

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getMinutes()

Returns the minutes component.

getMinutes(): number

Returns: Minutes (0-59)

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getSeconds()

Returns the seconds component.

getSeconds(): number

Returns: Seconds (0-59)

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getMilliseconds()

Returns the milliseconds component.

getMilliseconds(): number

Returns: Milliseconds (0-999)

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getTime()

Returns the timestamp in milliseconds since Unix epoch.

getTime(): number

Returns: Timestamp in milliseconds

Example:

const date = new NepaliDate();
console.log(date.getTime()); // 1736848800000

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getEnglishDate()

Returns the equivalent Gregorian (AD) date as a JavaScript Date object.

getEnglishDate(): Date

Returns: JavaScript Date object

Example:

const nepaliDate = new NepaliDate(2082, 9, 1);
const englishDate = nepaliDate.getEnglishDate();
console.log(englishDate.toISOString()); // '2026-01-14T...'

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Setter Methods

setYear()

Sets the Nepali year.

setYear(year: number): void

Parameters:

• year - Nepali year to set

Example:

const date = new NepaliDate(2082, 9, 15);
date.setYear(2083);
console.log(date.getYear()); // 2083

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setMonth()

Sets the Nepali month.

setMonth(month: number): void

Parameters:

• month - Nepali month (0-11)

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setDate()

Sets the day of month.

setDate(day: number): void

Parameters:

• day - Day of month (1-32)

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set()

Sets year, month, and day at once.

set(year: number, month: number, day: number): void

Parameters:

• year - Nepali year
• month - Nepali month (0-11)
• day - Day of month (1-32)

Example:

const date = new NepaliDate();
date.set(2082, 9, 15);
console.log(date.toString()); // '2082/10/15'

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Formatting Methods

format()

Formats the date according to a format string.

format(formatStr: string): string

Parameters:

• formatStr - Format pattern string

Returns: Formatted date string

English Format Tokens (Uppercase)

Token	Description	Example
YYYY	Full year	2082
YY	2-digit year	82
MM	Month with leading zero	01-12
M	Month without leading zero	1-12
MMM	Short month name	Bai, Jes, Mag
MMMM	Full month name	Baisakh, Magh
DD	Day with leading zero	01-32
D	Day without leading zero	1-32
DDD	Short day name	Sun, Mon
DDDD	Full day name	Sunday, Monday

Nepali Format Tokens (Lowercase)

Token	Description	Example
yyyy	Full year in Nepali	२०८२
yy	2-digit year in Nepali	८२
mm	Month with leading zero	०१-१२
m	Month without leading zero	१-१२
mmm	Short month name	बै, जे, मा
mmmm	Full month name	बैशाख, माघ
dd	Day with leading zero	०१-३२
d	Day without leading zero	१-३२
ddd	Short day name	आइत, सोम
dddd	Full day name	आइतबार, सोमबार

Examples:

const date = new NepaliDate(2082, 9, 15);

// English formats
console.log(date.format("YYYY-MM-DD")); // '2082-10-15'
console.log(date.format("MMMM DD, YYYY")); // 'Magh 15, 2082'
console.log(date.format("MMM D, YYYY")); // 'Mag 15, 2082'
console.log(date.format("DDDD, MMMM DD")); // 'Wednesday, Magh 15'

// Nepali formats
console.log(date.format("yyyy-mm-dd")); // '२०८२-१०-१५'
console.log(date.format("mmmm dd, yyyy")); // 'माघ १५, २०८२'
console.log(date.format("dddd, mmmm dd")); // 'बुधबार, माघ १५'

// Mixed format with literal text
console.log(date.format('YYYY"/"MM"/"DD')); // '2082/10/15'

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toString()

Returns the date as a string in YYYY/MM/DD format with 1-indexed month.

toString(): string

Returns: Date string (e.g., '2082/10/15')

Example:

const date = new NepaliDate(2082, 9, 15);
console.log(date.toString()); // '2082/10/15'

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parse()

Parses a date string and updates the current instance.

parse(dateString: string): void

Parameters:

• dateString - Date string in format YYYY-MM-DD, YYYY/MM/DD, or YYYY.MM.DD

Example:

const date = new NepaliDate();
date.parse("2082-10-15");
console.log(date.getYear()); // 2082
console.log(date.getMonth()); // 9
console.log(date.getDate()); // 15

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Date Manipulation Methods

addDays()

Adds the specified number of days and returns a new instance.

addDays(days: number): NepaliDate

Parameters:

• days - Number of days to add (can be negative)

Returns: New NepaliDate instance

Example:

const date = new NepaliDate(2082, 9, 15);
const tomorrow = date.addDays(1);
const lastWeek = date.addDays(-7);
console.log(tomorrow.format("YYYY-MM-DD")); // '2082-10-16'

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addMonths()

Adds the specified number of months and returns a new instance.

addMonths(months: number): NepaliDate

Parameters:

• months - Number of months to add (can be negative)

Returns: New NepaliDate instance

Example:

const date = new NepaliDate(2082, 9, 15);
const nextMonth = date.addMonths(1);
console.log(nextMonth.format("YYYY-MM-DD")); // '2082-11-15'

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addYears()

Adds the specified number of years and returns a new instance.

addYears(years: number): NepaliDate

Parameters:

• years - Number of years to add (can be negative)

Returns: New NepaliDate instance

Example:

const date = new NepaliDate(2082, 9, 15);
const nextYear = date.addYears(1);
console.log(nextYear.format("YYYY-MM-DD")); // '2083-10-15'

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Date Comparison Methods

diff()

Calculates the difference between two dates.

diff(date: NepaliDate, unit: 'year' | 'month' | 'day'): number

Parameters:

• date - NepaliDate to compare with
• unit - Unit of difference ('year', 'month', or 'day')

Returns: Difference in the specified unit

Example:

const date1 = new NepaliDate(2082, 5, 10);
const date2 = new NepaliDate(2082, 5, 20);

console.log(date1.diff(date2, "day")); // -10
console.log(date2.diff(date1, "day")); // 10
console.log(date1.diff(date2, "month")); // 0

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isAfter()

Checks if this date comes after the specified date.

isAfter(date: NepaliDate): boolean

Parameters:

• date - Date to compare with

Returns: true if this date is after the specified date

Example:

const date1 = new NepaliDate(2082, 9, 20);
const date2 = new NepaliDate(2082, 9, 15);
console.log(date1.isAfter(date2)); // true

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isBefore()

Checks if this date comes before the specified date.

isBefore(date: NepaliDate): boolean

Parameters:

• date - Date to compare with

Returns: true if this date is before the specified date

Example:

const date1 = new NepaliDate(2082, 9, 10);
const date2 = new NepaliDate(2082, 9, 15);
console.log(date1.isBefore(date2)); // true

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isEqual()

Checks if this date is exactly equal to the specified date (year, month, day).

isEqual(date: NepaliDate): boolean

Parameters:

• date - Date to compare with

Returns: true if dates are equal

Example:

const date1 = new NepaliDate(2082, 9, 15);
const date2 = new NepaliDate(2082, 9, 15);
console.log(date1.isEqual(date2)); // true

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isSame()

Checks if this date is the same as the specified date for the given unit.

isSame(date: NepaliDate, unit: 'year' | 'month' | 'day'): boolean

Parameters:

• date - Date to compare with
• unit - Unit to compare ('year', 'month', or 'day')

Returns: true if dates are the same for the specified unit

Example:

const date1 = new NepaliDate(2082, 9, 10);
const date2 = new NepaliDate(2082, 9, 20);

console.log(date1.isSame(date2, "year")); // true
console.log(date1.isSame(date2, "month")); // true
console.log(date1.isSame(date2, "day")); // false

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Date Range Methods

startOfDay()

Returns a new NepaliDate set to the start of the current day (00:00:00).

startOfDay(): NepaliDate

Returns: New NepaliDate at start of day

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endOfDay()

Returns a new NepaliDate set to the end of the current day (23:59:59.999).

endOfDay(): NepaliDate

Returns: New NepaliDate at end of day

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startOfWeek()

Returns a new NepaliDate representing the start of the week.

startOfWeek(startOfWeek: number = 0): NepaliDate

Parameters:

• startOfWeek - Day to consider as start of week (0-6, 0 = Sunday). Default: 0

Returns: New NepaliDate at start of week

Example:

const date = new NepaliDate(2082, 9, 15); // Wednesday
const weekStart = date.startOfWeek(); // Previous Sunday
const weekStartMon = date.startOfWeek(1); // Previous Monday

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endOfWeek()

Returns a new NepaliDate representing the end of the week.

endOfWeek(startOfWeek: number = 0): NepaliDate

Parameters:

• startOfWeek - Day to consider as start of week (0-6, 0 = Sunday). Default: 0

Returns: New NepaliDate at end of week

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startOfMonth()

Returns a new NepaliDate representing the first day of the month.

startOfMonth(): NepaliDate

Returns: New NepaliDate at first day of month

Example:

const date = new NepaliDate(2082, 9, 15);
const monthStart = date.startOfMonth();
console.log(monthStart.format("YYYY-MM-DD")); // '2082-10-01'

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endOfMonth()

Returns a new NepaliDate representing the last day of the month.

endOfMonth(): NepaliDate

Returns: New NepaliDate at last day of month

Example:

const date = new NepaliDate(2082, 9, 15);
const monthEnd = date.endOfMonth();
console.log(monthEnd.format("YYYY-MM-DD")); // '2082-10-29'

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startOfYear()

Returns a new NepaliDate representing the first day of the year (1st Baisakh).

startOfYear(): NepaliDate

Returns: New NepaliDate at first day of year

Example:

const date = new NepaliDate(2082, 9, 15);
const yearStart = date.startOfYear();
console.log(yearStart.format("YYYY-MM-DD")); // '2082-01-01'

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endOfYear()

Returns a new NepaliDate representing the last day of the year (last day of Chaitra).

endOfYear(): NepaliDate

Returns: New NepaliDate at last day of year

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Date Information Methods

daysInMonth()

Returns the number of days in the current month.

daysInMonth(): number

Returns: Number of days (29-32)

Example:

const date = new NepaliDate(2082, 9, 15); // Magh 2082
console.log(date.daysInMonth()); // 29

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isLeapYear()

Checks if the current year is a leap year in the Nepali calendar.

isLeapYear(): boolean

Returns: true if leap year

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getWeeksInMonth()

Calculates the number of weeks in the current month.

getWeeksInMonth(): number

Returns: Number of weeks

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Quarter Methods

getCurrentQuarter()

Returns the quarter number (1-4) for the current date.

getCurrentQuarter(): number

Returns: Quarter number (1-4)

Example:

const date = new NepaliDate(2082, 9, 15); // Magh = Q4
console.log(date.getCurrentQuarter()); // 4

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getCurrentFiscalYearQuarter()

Returns the current fiscal year quarter number (1-4).

getCurrentFiscalYearQuarter(): number

Returns: Fiscal year quarter number (1-4)

Fiscal Year

Nepal's fiscal year starts from Shrawan 1st (month index 3). So:

• Q1: Shrawan - Ashwin (months 3-5)
• Q2: Kartik - Poush (months 6-8)
• Q3: Magh - Chaitra (months 9-11)
• Q4: Baisakh - Asar (months 0-2)

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getCurrentFiscalYearQuarterDates()

Returns the start and end dates of the current fiscal year quarter.

getCurrentFiscalYearQuarterDates(): { start: NepaliDate; end: NepaliDate }

Returns: Object with start and end NepaliDate instances

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Utility Methods

clone()

Creates a copy of the current NepaliDate instance.

clone(): NepaliDate

Returns: New NepaliDate with same date and time

Example:

const date = new NepaliDate(2082, 9, 15);
const copy = date.clone();
copy.setDate(20);
console.log(date.getDate()); // 15 (unchanged)
console.log(copy.getDate()); // 20

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isValid() (Instance)

Checks if the current NepaliDate instance contains a valid date.

isValid(): boolean

Returns: true if valid