Class HDate

A HDate represents a Hebrew calendar date.

An instance of this class encapsulates a date in the Hebrew calendar system. It consists of a year, month, and day, without any associated time or location data. The Hebrew calendar is a lunisolar calendar, meaning it is based on both lunar and solar cycles.

A Hebrew date internally stores three numbers:

year: The Hebrew year (1-9999). Counted from the traditional Hebrew date of creation (3761 BCE in the Gregorian calendar)
month: The Hebrew month (1-13). Month 1 is Nisan, month 7 is Tishrei. There are 12 months in a regular year and 13 months in a leap year.
day: The day of the month (1-30)

This class uses Rata Die to convert between the Hebrew and Gregorian calendars.

To calculate times of day, use Zmanim class from @hebcal/core

See

Constructors

constructor

new HDate(day?, month?, year?): HDate
Create a Hebrew date. There are 3 basic forms for the HDate() constructor.
1. No parameters - represents the current Hebrew date at time of instantiation
2. One parameter
  - Date - represents the Hebrew date corresponding to the Gregorian date using local time. Hours, minutes, seconds and milliseconds are ignored.
  - HDate - clones a copy of the given Hebrew date
  - number - Converts absolute R.D. days to Hebrew date. R.D. 1 == the imaginary date January 1, 1 (Gregorian)
3. Three parameters: Hebrew day, Hebrew month, Hebrew year. Hebrew day should be a number between 1-30, Hebrew month can be a number or string, and Hebrew year is always a number.
Parameters
- Optionalday:
      | number
      | Date
      | SimpleHebrewDate
      | HDate
  Day of month (1-30) if a number. If a Date is specified, represents the Hebrew date corresponding to the Gregorian date using local time. If an HDate is specified, clones a copy of the given Hebrew date.
- Optionalmonth: string | number
  Hebrew month of year (1=NISAN, 7=TISHREI)
- Optionalyear: number
  Hebrew year
Returns HDate
Example
```
import {HDate, months} from '@hebcal/hdate';

const hd1 = new HDate();
const hd2 = new HDate(new Date(2008, 10, 13));
const hd3 = new HDate(15, 'Cheshvan', 5769);
const hd4 = new HDate(15, months.CHESHVAN, 5769);
const hd5 = new HDate(733359); // ==> 15 Cheshvan 5769
const monthName = 'אייר';
const hd6 = new HDate(5, monthName, 5773);
```
- Defined in hdate.ts:111

Properties

dd

dd: number

Hebrew day within the month (1-30)

mm

mm: number

Hebrew month of year (1=NISAN, 7=TISHREI)

`Optional`rd

rd?: number

absolute Rata Die (R.D.) days

yy

yy: number

Hebrew year, 1-9999

Methods

abs

abs(): number
Converts from Hebrew date representation to R.D. (Rata Die) fixed days. R.D. 1 is the imaginary date Monday, January 1, 1 (Gregorian). Note also that R.D. = Julian Date − 1,721,424.5

Returns number
See
Rata Die

Example
```
const hd = new HDate(15, 'Cheshvan', 5769);
hd.abs(); // 733359
```
- Defined in hdate.ts:266

add

add(amount, units?): HDate
Returns a cloned HDate object with a specified amount of time added

Units are case insensitive, and support plural and short forms. Note, short forms are case sensitive.

Unit Shorthand Description

day d days

week w weeks

month M months

year y years
Parameters
- amount: string | number
- units: string = 'd'
Returns HDate
- Defined in hdate.ts:440

Unit	Shorthand	Description
`day`	`d`	days
`week`	`w`	weeks
`month`	`M`	months
`year`	`y`	years

after

after(dayOfWeek): HDate

Returns an HDate corresponding to the specified day of week after this Hebrew date

Parameters

dayOfWeek: number
day of week: Sunday=0, Saturday=6

Returns HDate

Example

new HDate(new Date('Wednesday February 19, 2014')).after(6).greg() // Sat Feb 22 2014
new HDate(new Date('Saturday February 22, 2014')).after(6).greg() // Sat Mar 01 2014
new HDate(new Date('Sunday February 23, 2014')).after(6).greg() // Sat Mar 01 2014

before

before(dayOfWeek): HDate
Returns an HDate corresponding to the specified day of week before this Hebrew date
Parameters
- dayOfWeek: number
  day of week: Sunday=0, Saturday=6
Returns HDate
Example
```
new HDate(new Date('Wednesday February 19, 2014')).before(6).greg() // Sat Feb 15 2014
```
- Defined in hdate.ts:352

daysInMonth

daysInMonth(): number
Number of days in the month of this Hebrew date (29 or 30)

Returns number
an integer 29-30
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.daysInMonth(); // 29
```
- Defined in hdate.ts:214

deltaDays

deltaDays(other): number
Returns the difference in days between the two given HDates.

The result is positive if this date is comes chronologically after the other date, and negative if the order of the two dates is reversed.

The result is zero if the two dates are identical.
Parameters
- other: HDate
  Hebrew date to compare
Returns number
Example
```
import {HDate, months} from '@hebcal/hdate';

const hd1 = new HDate(25, months.KISLEV, 5770);
const hd2 = new HDate(15, months.CHESHVAN, 5769);
const days = hd1.deltaDays(hd2); // 394
```
- Defined in hdate.ts:508

getDate

getDate(): number

Gets the day within the month (1-30)

Returns number

an integer 1-30

Example

const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getDate(); // 15

getDay

getDay(): number
Returns the day of the week for this Hebrew date, where 0 represents Sunday, 1 represents Monday, 6 represents Saturday.

For the day of the month, see getDate()

Returns number
an integer 0-6
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getDate(); // 4
```
- Defined in hdate.ts:239

getFullYear

getFullYear(): number

Returns the Hebrew year of this Hebrew date

Returns number

an integer >= 1

Example

const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getFullYear(); // 5769

getMonth

getMonth(): number
Returns the Hebrew month (1=NISAN, 7=TISHREI) of this Hebrew date

Returns number
an integer 1-13
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getMonth(); // 8
```
- Defined in hdate.ts:191

getMonthName

getMonthName(): string

Returns a transliterated Hebrew month name, e.g. 'Elul' or 'Cheshvan'.

Returns string

Example

const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getMonthName(); // 'Cheshvan'

getTishreiMonth

getTishreiMonth(): number
The Tishrei-based month of this Hebrew date. 1 is Tishrei, 7 is Nisan, 13 is Elul in a leap year

Returns number
an integer 1-13
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.getTishreiMonth(); // 2
```
- Defined in hdate.ts:202

greg

greg(): Date
Converts this Hebrew date to the corresponding Gregorian date. Note that this function returns the daytime portion of the date. For example, the 15th of Cheshvan 5769 began at sundown on 12 November 2008 and continues through 13 November 2008. This function would return only the date 13 November 2008.

Returns Date
Example
```
const hd = new HDate(15, 'Cheshvan', 5769);
hd.greg(); // 13 November 2008
```
- Defined in hdate.ts:253

isLeapYear

isLeapYear(): boolean
Returns true if this Hebrew date occurs during a Hebrew leap year

Returns boolean
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.isLeapYear(); // false
```
- Defined in hdate.ts:180

isSameDate

isSameDate(other): boolean
Compares this Hebrew date to another date, returning true if the dates match.
Parameters
- other: HDate
  Hebrew date to compare
Returns boolean
Example
```
const hd1 = new HDate(new Date(2008, 10, 13));
const hd2 = new HDate(15, 'Cheshvan', 5769);
hd1.isSameDate(hd2); // true
```
- Defined in hdate.ts:520

nearest

nearest(dayOfWeek): HDate

Returns an HDate corresponding to the specified day of week nearest to this Hebrew date

Parameters

dayOfWeek: number
day of week: Sunday=0, Saturday=6

Returns HDate

Example

new HDate(new Date('Wednesday February 19, 2014')).nearest(6).greg() // Sat Feb 22 2014
new HDate(new Date('Tuesday February 18, 2014')).nearest(6).greg() // Sat Feb 15 2014

next(): HDate

Returns the next Hebrew date

Returns HDate

Example

const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.next(); // '16 Cheshvan 5769'

onOrAfter

onOrAfter(dayOfWeek): HDate

Returns an HDate corresponding to the specified day of week on or after this Hebrew date

Parameters

dayOfWeek: number
day of week: Sunday=0, Saturday=6

Returns HDate

Example

new HDate(new Date('Wednesday February 19, 2014')).onOrAfter(6).greg() // Sat Feb 22 2014
new HDate(new Date('Saturday February 22, 2014')).onOrAfter(6).greg() // Sat Feb 22 2014
new HDate(new Date('Sunday February 23, 2014')).onOrAfter(6).greg() // Sat Mar 01 2014

onOrBefore

onOrBefore(dayOfWeek): HDate

Returns an HDate corresponding to the specified day of week on or before this Hebrew date

Parameters

dayOfWeek: number
day of week: Sunday=0, Saturday=6

Returns HDate

Example

new HDate(new Date('Wednesday February 19, 2014')).onOrBefore(6).greg() // Sat Feb 15 2014
new HDate(new Date('Saturday February 22, 2014')).onOrBefore(6).greg() // Sat Feb 22 2014
new HDate(new Date('Sunday February 23, 2014')).onOrBefore(6).greg() // Sat Feb 22 2014

prev(): HDate

Returns the previous Hebrew date

Returns HDate

Example

const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.prev(); // '14 Cheshvan 5769'

render

render(locale?, showYear?): string

Renders this Hebrew date as a translated or transliterated string, including ordinal e.g. '15th of Cheshvan, 5769'.

Parameters

Optionallocale: string
Optional locale name (defaults to active locale).
OptionalshowYear: boolean = true
Display year (defaults to true).

Returns string

Example

import {HDate, months} from '@hebcal/hdate';

const hd = new HDate(15, months.CHESHVAN, 5769);
console.log(hd.render('en')); // '15th of Cheshvan, 5769'
console.log(hd.render('he')); // '15 חֶשְׁוָן, 5769'
console.log(hd.render('en', false)); // '15th of Cheshvan'
console.log(hd.render('he', false)); // '15 חֶשְׁוָן'

See

Locale

renderGematriya

renderGematriya(suppressNikud?): string

Renders this Hebrew date in Hebrew gematriya, regardless of locale.

Parameters

suppressNikud: boolean = false

Returns string

Example

import {HDate, months} from '@hebcal/hdate';
const hd = new HDate(15, months.CHESHVAN, 5769);
hd.renderGematriya(); // 'ט״ו חֶשְׁוָן תשס״ט'
hd.renderGematriya(true); // 'ט״ו חשון תשס״ט'

subtract

subtract(amount, units?): HDate
Returns a cloned HDate object with a specified amount of time subracted

Units are case insensitive, and support plural and short forms. Note, short forms are case sensitive.

Unit Shorthand Description

day d days

week w weeks

month M months

year y years
Parameters
- amount: number
- units: string = 'd'
Returns HDate
Example
```
import {HDate, months} from '@hebcal/hdate';

const hd1 = new HDate(15, months.CHESHVAN, 5769);
const hd2 = hd1.add(1, 'weeks'); // 7 Kislev 5769
const hd3 = hd1.add(-3, 'M'); // 30 Av 5768
```
- Defined in hdate.ts:488

Unit	Shorthand	Description
`day`	`d`	days
`week`	`w`	weeks
`month`	`M`	months
`year`	`y`	years

toString

toString(): string
Returns a string representation of this Hebrew date using English transliterations

Returns string
Example
```
const hd = new HDate(new Date(2008, 10, 13)); // 15 Cheshvan 5769
hd.toString(); // '15 Cheshvan 5769'
```
- Defined in hdate.ts:530

`Static`dayOnOrBefore

dayOnOrBefore(dayOfWeek, absdate): number
Convenience function for determining the R.D. date near a specified R.D. date, corresponding to the specified day of week.

Note: Applying this function to d+6 gives us the dayOfWeek on or after an absolute day d. Similarly, applying it to d+3 gives the dayOfWeek nearest to absolute date d, applying it to d-1 gives the dayOfWeek previous to absolute date d, and applying it to d+7 gives the dayOfWeek following absolute date d.
Parameters
- dayOfWeek: number
  day of week: Sunday=0, Saturday=6
- absdate: number
Returns number
- Defined in hdate.ts:669

`Static`daysInMonth

daysInMonth(month, year): number
Number of days in Hebrew month in a given year (29 or 30)
Parameters
- month: number
  Hebrew month (e.g. months.TISHREI)
- year: number
  Hebrew year
Returns number
Example
```
import {HDate, months} from '@hebcal/hdate';
HDate.daysInMonth(months.CHESHVAN, 5769); // 29
```
- Defined in hdate.ts:567

`Static`daysInYear

daysInYear(year): number
Number of days in the Hebrew year. Regular years can have 353, 354, or 355 days. Leap years can have 383, 384, or 385 days.
Parameters
- year: number
  Hebrew year
Returns number
Example
```
HDate.daysInYear(5783); // 355
HDate.daysInYear(5784); // 383
```
- Defined in hdate.ts:614

`Static`fromGematriyaString

fromGematriyaString(str, currentThousands?): HDate

Construct a new instance of HDate from a Gematriya-formatted string

Parameters

str: string
currentThousands: number = 5000

Returns HDate

Example

HDate.fromGematriyaString('כ״ז בְּתַמּוּז תשפ״ג') // 27 Tamuz 5783
HDate.fromGematriyaString('כ׳ סיון תש״ד') // 20 Sivan 5704
HDate.fromGematriyaString('ה׳ אִיָיר תש״ח') // 5 Iyyar 5708

`Static`getMonthName

getMonthName(month, year): string
Returns a transliterated string name of Hebrew month in year, for example 'Elul' or 'Cheshvan'.
Parameters
- month: number
  Hebrew month (e.g. months.TISHREI)
- year: number
  Hebrew year
Returns string
Example
```
import {HDate, months} from '@hebcal/hdate';
HDate.getMonthName(months.CHESHVAN, 5769); // 'Cheshvan'
```
- Defined in hdate.ts:580

`Static`hebrew2abs

hebrew2abs(year, month, day): number
Converts Hebrew date to R.D. (Rata Die) fixed days. R.D. 1 is the imaginary date Monday, January 1, 1 on the Gregorian Calendar.
Parameters
- year: number
  Hebrew year
- month: number
  Hebrew month (1=NISAN, 7=TISHREI)
- day: number
  Hebrew date (1-30)
Returns number
Example
```
import {HDate, months} from '@hebcal/hdate';
HDate.hebrew2abs(5769, months.CHESHVAN, 15); // 733359
```
- Defined in hdate.ts:284

`Static`isHDate

isHDate(obj): boolean

Tests if the object is an instance of HDate

Parameters

obj: any

Returns boolean

Example

HDate.isHDate(new HDate()); // true
HDate.isHDate(new Date()); // false
HDate.isHDate(null); // false
HDate.isHDate(12345); // false
HDate.isHDate('15 Cheshvan 5769'); // false

`Static`isLeapYear

isLeapYear(year): boolean
Returns true if Hebrew year is a leap year
Parameters
- year: number
  Hebrew year
Returns boolean
Example
```
HDate.isLeapYear(5783); // false
HDate.isLeapYear(5784); // true
```
- Defined in hdate.ts:544

`Static`longCheshvan

longCheshvan(year): boolean
true if Cheshvan is long in Hebrew year
Parameters
- year: number
  Hebrew year
Returns boolean
Example
```
HDate.longCheshvan(5783); // true
HDate.longCheshvan(5784); // false
```
- Defined in hdate.ts:625

`Static`monthFromName

monthFromName(monthName): number

Converts Hebrew month string name to numeric

Parameters

monthName: string | number

Returns number

Example

import {HDate, months} from '@hebcal/hdate';
HDate.monthFromName(months.CHESHVAN); // 8
HDate.monthFromName('Cheshvan'); // 8
HDate.monthFromName('חשון'); // 8

`Static`monthNum

monthNum(month): number
Returns the Hebrew month number (NISAN=1, TISHREI=7)
Parameters
- month: string | number
  A number, or Hebrew month name string
Returns number
Example
```
import {HDate, months} from '@hebcal/hdate';
HDate.monthNum(months.CHESHVAN); // 8
HDate.monthNum('Cheshvan'); // 8
HDate.monthNum('חשון'); // 8
```
- Defined in hdate.ts:593

`Static`monthsInYear

monthsInYear(year): number
Number of months in this Hebrew year (either 12 or 13 depending on leap year)
Parameters
- year: number
  Hebrew year
Returns number
Example
```
HDate.monthsInYear(5783); // 12
HDate.monthsInYear(5784); // 13
```
- Defined in hdate.ts:555

`Static`shortKislev

shortKislev(year): boolean
true if Kislev is short in Hebrew year
Parameters
- year: number
  Hebrew year
Returns boolean
Example
```
HDate.shortKislev(5783); // false
HDate.shortKislev(5784); // true
```
- Defined in hdate.ts:636

Class HDate

See

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns HDate

Example

Properties

dd

mm

Optionalrd

yy

Methods

abs

Returns number

See

Example

add

Parameters

Returns HDate

after

Parameters

Returns HDate

Example

before

Parameters

Returns HDate

Example

daysInMonth

Returns number

Example

deltaDays

Parameters

Returns number

Example

getDate

Returns number

Example

getDay

Returns number

Example

getFullYear

Returns number

Example

getMonth

Returns number

Example

getMonthName

Returns string

Example

getTishreiMonth

Returns number

Example

greg

Returns Date

Example

isLeapYear

Returns boolean

Example

isSameDate

Parameters

Returns boolean

Example

nearest

Parameters

Returns HDate

Example

next

Returns HDate

Example

onOrAfter

Parameters

Returns HDate

Example

onOrBefore

Parameters

`Optional`rd

`Static`dayOnOrBefore

`Static`daysInMonth

`Static`daysInYear

`Static`fromGematriyaString

`Static`getMonthName

`Static`hebrew2abs

`Static`isHDate

`Static`isLeapYear

`Static`longCheshvan

`Static`monthFromName

`Static`monthNum

`Static`monthsInYear

`Static`shortKislev