Hebcal JavaScript

Original C written by Danny Sadinoff, with portions by Michael J. Radwin. 2014 JavaScript port by Eyal Schachter (age 15).

Description

Hebcal JS is a JavaScript API to aid working with the Hebrew calendar. It is available for both browser and Node.JS.

It can convert between Hebrew and Gregorian dates, get weekly sedra, holidays, and halachik times (zemanim).

You can include it in a client-side (browser) script with the hebcal.min.js script in the client subfolder (17KB gzipped). It exposes a global variable, Hebcal. For Node, install hebcal from NPM...

$ npm install hebcal

...and include Hebcal with var Hebcal = require('hebcal');

Hebcal JS is currently at version 2.3.2. It is approximately equivalent to Hebcal C 3.15. I (Eyal) did not write Hebcal JS 1.0. 2.x is a nearly-complete rewrite of it.

The version documented here is 2.3.2.

Releases

• 2.0.0 - 2014-02-18 (19 Adar 1 5774)
• 2.1.0 - 2014-03-16 (14 Adar 2 5774 [Purim])
• 2.1.1 - 2014-04-04 (5 Nisan 5774)
• 2.1.2 - 2014-04-04 (5 Nisan 5774)
• 2.2.0 - 2014-06-29 (1 Tamuz 5774)
• 2.2.1 - 2016-04-17 (9 Nisan 5776)
• 2.2.2 - 2016-04-18 (10 Nisan 5776)
• 2.2.3 - 2017-02-14 (18 Shvat 5777)
• 2.2.4 - 2017-05-17 (21 Iyyar 5777)
• 2.2.5 - 2017-07-02 (8 Tamuz 5777)
• 2.2.6 - 2017-10-29 (10 Cheshvan 5778)
• 2.3.0 - 2019-02-11 (6 Adar 1 5779)
• 2.3.1 - 2019-02-11 (6 Adar 1 5779)
• 2.3.2 - 2019-09-25 (25 Elul 5779)

Contributors

Hebcal JS was ported from C by Eyal Schachter (Scimonster).

The original C and JavaScript code was written by Danny Sadinoff, with contributions by Michael J. Radwin.

Various other people have made contributions on GitHub.

License / Distribution

Copyright (C) 1994-2011 Danny Sadinoff Portions Copyright (c) 2011 Michael J. Radwin. All Rights Reserved.

Hebcal JavaScript is distributed under the GNU Public License version 3. The original Hebcal C is under the GPLv2. The program and its source code may be freely distributed. For details, see the file COPYING in the distribution.

Remember, the GPL means you can't use this in a closed-source program! (But see #72)

If you are using this program, I'd like to hear about -- know who you are, what version you're using, and how you're using Hebcal, and anything else you'd like to tell me, so that i can adjust the program to meet users' needs.

The original Hebcal is at hebcal/hebcal.

API

This is where every property and method is listed.

• CLI
• Hebcal
• Hebcal.HDate
• Hebcal.Month
• Hebcal.GregYear
• Hebcal.GregMonth
• Hebcal.cities
• Hebcal.holidays
• Hebcal.events
• Utilities:
• • gematriya
• • range

Information on certain standards

Descriptions

Sometimes a "description array" will be mentioned. This is an array with between 1 and 3 properties: [Sfardit pronunciation[, Ashkenazis pronunciation[, Hebrew spelling]]].

Methods that fetch a value from this array expect one of the following strings: "a" for Ashkenazis, "h", for Hebrew, and anything else for Sfardit.

Month names

Hebcal is not too particular about month names, and only checks up to the second letter. That means that, despite being totally incorrect, "cheese" will return the same value as "cheshvan". Month names work in both Hebrew and English.

Nisan, Iyyar, Sivan, Tamuz, Av, Elul, Tishrei, Cheshvan, Kislev, Tevet, Shvat, Adar (1, 2). ניסן, אייר, סיון, תמוז, אב, אלול, תשרי, חשון, כסלו, טבת, שבט, אדר (1, 2).

Sun times

Hebcal JS uses the SunCalc JavaScript library to calculate sun times. They do not provide an accuracy claim, but i have found their times to be up to 3 minutes off from the accepted times. Do not rely on Zemanim until the last moment!

Finding location in browser

Both scripts run on the exact same code, except for one thing. In the browser, Hebcal will attempt to set Hebcal.defaultLocation to the user's location using the geolocation API. The ready event (see Hebcal.events) is fired once the location has been obtained, or failed to be obtained.

This will cause any webpages with the Hebcal script to request the user's permission to view their location. If they deny it, the default location will be [0, 0].

To turn off this feature, use the hebcal.noloc.min.js script instead of the usual hebcal.min.js script. The unminified version is hebcal.noloc.js. All of these files are in the client folder.

Source maps

When using Hebcal JS in the browser, it may be helpful for debugging to include a sourcemap file for browsers that support it. Both minified and unminified, regular and noloc, have a sourcemap file. This is <js filename>.map.

Ordering in this documentation

Be forewarned: the ordering of properties/methods in this documentation is almost completely arbitrary. It mostly follows the order of the code, which is itself written in pretty much whatever order i decided i needed those methods. If you're looking for a specific thing, i highly recommend using your browser's find tool (ctrl+f, or cmd+f for you Mac types). If you just want to know everything about Hebcal JS, just start at the top and work your way down.

Command line interface

Hebcal JS (as of v2.1) also provides a simple CLI. It's mainly for just testing output. If you really need an advanced CLI, use the main Hebcal code.

You can access this CLI by installing Hebcal JS globally from NPM:

npm install -g hebcal

This exposes the hebcaljs command. This is to differentiate it from the ordinary hebcal command.

For usage information, run hebcaljs -h.

Hebcal

The global variable (if running in the browser) Hebcal is the entrypoint to Hebcal. It is a constructor returning an object represtenting a Hebrew year, and also has many other properties.

new Hebcal([year[, month]]);

year, if provided, should be an int representing a Hebrew year, for example, 5774. If it is falsey (includes null, undefined, 0, false, etc), it defaults to the current year. If it is not falsy, and not a number, Hebcal will throw an error.

month, if provided, supports multiple types:

• String -- The name of a single month.
• Number -- The number of a single month (Nisan is 1, Tishrei 7).
• Array -- An array of either of the above two, or mixed. Basically, anything that can be passed to Hebcal.Month (see below).

If not provided, it defaults to all of the months in the given year. If it is a different type, Hebcal will throw an error.

To get the full current year:

var year = new Hebcal();

Properties on Hebcal instances

Hebcal.prototype.year

Number. The year represented in the Hebcal. (Not actually a prototype value.)

Hebcal.prototype.months

Array of Hebcal.Months. Is not intended to be used directly, but rather with the getMonth() and map() methods. (Not actually a prototype value.)

Hebcal.prototype.holidays

v2.2 and later: An object, with keys as HDate strings, and values are arrays of Hebcal.holidays.Events. It is not recommended to use this object directly. Instead, use HDate().holidays() for fetching and Hebcal().addHoliday() for adding.

BEFORE v2.2: Array of holidays, as Hebcal.holidays.Events, for the represented year.

Not actually a prototype value.

Hebcal.prototype.length

Number of days in the year. (Not actually a prototype value.)

Hebcal.prototype.il

Boolean get/set. Whether the current location is in Israel or not. This is relevant with regards to holidays. This gets set by Hebcal.defaultCity, and year.setCity(). It's possible that you may have to set it yourself in certain circumstances. (Not actually a prototype value.)

Hebcal.prototype.lat and long

Number get/sets. The latitude and longitude of the current location. This is relevant with regards to getting times for dates. (Not actually prototype values.) Default: 0.

Hebcal.prototype.setCity(city)

year.setCity('Jerusalem');

Sets the lat/long to the given city's location. Returns the Hebcal it was called upon. This allows for easy method chaining.

For more information regarding cities, see Hebcal.cities below.

Hebcal.prototype.setLocation(latitude, longitude)

year.setLocation(40.716, -74.016); // coords of New York

Sets the lat/long to the given location. Returns the Hebcal it was called upon.

Hebcal.prototype.isLeapYear()

var isleap = year.isLeapYear();

Takes 0 arguments, returns a boolean.

Hebcal.prototype.next()

var nextYear = year.next();

Takes 0 arguments, returns Hebcal representing the following year.

Hebcal.prototype.prev()

var prevYear = year.prev();

Takes 0 arguments, returns Hebcal representing the preceding year.

Hebcal.prototype.getMonth(month)

var tishrei = year.getMonth(7);
var adar2 = year.getMonth(-1);
var shvat = year.getMonth('shvat');
var elul = year.getMonth('אלול');
var nextNisan = year.getMonth(13); // in a non-leap year

Takes a single argument, the month to get. Returns Hebcal.Month representing the requested month.

If the month is a positive number, it is a month index. Remember, Nisan is 1, Tishrei 7. If the month is a negative number, it is a month index from the end of the year. If the month is a string, it can be a month name in Hebrew or English.

Hebcal.prototype.getDay(day)

Takes a single argument, the day to get. day should be a number representing the number of days from Nisan 1. Nisan 1 is 1, Rosh Hashanah is usually a little above 200, but it can vary. Returns a Hebcal.HDate representing the requested day.

If the day is a positive number, it is a day index. If the day is a negative number, it is a day index from the end of the year. So, 1 would be the 29th of Elul.

Hebcal.prototype.days()

Return an array of all the days in the year. This method was added in Hebcal JS 2.1.

Hebcal.prototype.map(mapFunc[, thisArg])

In 2.0: A shortcut for year.months.map(mapFunc, [thisArg]).

In 2.1 and beyond: Map over each day in the year, calling mapFunc in context of thisArg. Returns an array.

Hebcal.prototype.filter(filterFunc[, thisArg])

Only keep days in the year that pass the filterFunc tester function. Returns an array of Hebcal.HDates. This method was added in Hebcal JS 2.1.

Hebcal.prototype.addHoliday(event)

Add a holiday to the list of holidays. Throws an error if event is not a Hebcal.holidays.Event. Returns the Hebcal it was called upon.

year.addHoliday(new Hebcal.holidays.Event(new Date(2014,0,1), 'New Years Day', Hebcal.holidays.masks.USER_EVENT));

See Hebcal.holidays for more information on creating an event.

Hebcal.prototype.findSedra(parsha, o)

Find the Shabbat on which a given parsha is read. The parsha name (first argument) should correspond to the language string ('s', 'a', or 'h') in the second argument. If no second argument is provided, the parsha should be in Sfardit.

As of v2.2.1, the language string is ignored and checks all languages by default.

This method was added in v2.1.

Hebcal.prototype.findParsha(parsha, o)

An alias of findSedra(). This method was added in v2.1.

Hebcal.prototype.find()

A "magical" method that allows finding dates in the year. It supports several types of arguments, and is extensible. Returns an array of Hebcal.HDates.

If called with a single argument:

• Hebcal.HDate: Find that Hebrew date in the year. This is useful, because getting a date specifically from the year, and not recreating it, gives it a few additional properties, such as a pre-set location, and a reference to the containing year.
• Date: Find that Gregorian date in the year.
• Array: An array of acceptible arguments to year.find(). If an item is an array, it is treated as passing multiple arguments to find().
• String: A description of a date. See find.strings below.

If called with two arguments: the first represents a day, or list of days, in a month; and the second represents a month, or list of months. The day is anything that can be passed to Hebcal.Month.prototype.find() (see below). If the month is a:

• Hebcal.Month: Search for the day in that month. This is usually used only internally; it's more user-friendly to use one of the other types.
• Number: A number to be given to Hebcal.prototype.getMonth().
• String: A month name.
• Array: An array of any of the above, mixed as you please.

Hebcal.prototype.find.strings

This is technically a function for internal use, but it also serves as the extension point for passing strings. Simply set a property on it, and that can be used as a string to Hebcal.prototype.find(). To let the passed string be more user-friendly, the following conversions are done: convert to lowercase; replace spaces with underscores. This means that "rosh chodesh", "Rosh Chodesh", and "ROSH_CHODESH" all evaluate to "rosh_chodesh".

The following properties are defined by default:

• rosh_chodesh (all roshei chodashim in the year)
• holidays (days with a holiday defined in year.holidays)
• omer (days in sefirat ha'omer)
• pesach
• sukkot (aliased as sukkos, succot, succos)
• shavuot (aliased as shavuos)
• rosh_hashana (aliased as rosh_hashanah)
• today
• yesterday
• tomorrow

To extend the list, add a property of Hebcal.prototype.find.strings. The name should be all lowercase, and spaces replaced with underscores, as described above. The property itself should be a function taking a no arguments. Within the function, this refers to the object that find() is being called on. It should return an Array. It is perfectly acceptible to return the result of another find() call.

Hebcal.addZeman(zeman, func)

An alias of Hebcal.HDate.addZeman. See there.

Hebcal.cities

Get locations for several cities around the world.

Hebcal.cities.getCity(cityName)

Returns an array describing the location of a city, or an array of 0s if the city wasn't found. This array is intended to be passed to Hebcal.cities.getLocation().

In v2.0: [/* number */ latdeg, /* number */ latmins, /* number */ longdeg, /* number */ longmins, /* boolean */ Israel]

In v2.1+: [/* number */ lat, /* number */ long, /* boolean */ Israel]

The old syntax also works.

Hebcal.cities.getLocation(cityInfo)

Is intended to receive the return value of getCity(). Returns an object containing 2 properties: lat and long, with the numbers in degrees, including minutes.

An end-user should rarely need either of these; they are mainly used by Hebcal.defaultCity and Hebcal.setCity() and the methods they call.

This method has been removed as of v2.1.1.

Hebcal.cities.listCities()

Return an array containing the names of all supported cities.

Hebcal.cities.addCity(city, info)

Add a city to the list of cities. The first argument should be the name, the second an array of the kind that getCity() returns. This method does not return anything.

Hebcal.cities.nearest(lat, long)

Return the name of the city nearest to the given coordinates.

The coordinates can be given either as numbers, or as arrays of [deg, mins]. The array format is deprecated as of v2.1.

Hebcal.defaultCity

String get/set. The nearest city to Hebcal.defaultLocation.

Hebcal.defaultLocation

Array of coordinates that are used as the default location when creating a new instance of Hebcal or Hebcal.HDate.

[latdeg, longdeg]

Hebcal.holidays

A holiday/event interface.

Hebcal.holidays.masks

An object containing bitmasks for use when creating a Hebcal.holidays.Event.

masks.USER_EVENT          = 1;
masks.LIGHT_CANDLES       = 2;
masks.YOM_TOV_ENDS        = 4;
masks.CHUL_ONLY           = 8; // chutz l'aretz (Diaspora)
masks.IL_ONLY             = 16; // b'aretz (Israel)
masks.LIGHT_CANDLES_TZEIS = 32;

Hebcal.holidays.IGNORE_YEAR

A constant to be passed to both Date and Hebcal.HDate constructors. It means run this holiday every year, not just one specific year. It is automatically applied to Gregorian dates.

This is removed as of Hebcal JS 2.2.0.

new Hebcal.holidays.Event(date, desc[, masks])

A constructor for Events. This is meant to be added to a holidays list.

date can be either a Gregorian Date object or a Hebcal.HDate object.

desc can be a description array, or string. A description array looks like: [Sfardit pronounciation[, Ashkenazis pronounciation[, Hebrew spelling]]]. If the Sfardit and Ashkenazis are the same, pass null for Ashkenazis.

masks should be a bitmask of the items in Hebcal.holidays.masks. I.e. Hebcal.holidays.masks.IL_ONLY | Hebcal.holidays.masks.YOM_TOV_ENDS.

Hebcal.holidays.Event.prototype.date

A Hebcal.HDate representing the date passed to the constructor. (Not actually a prototype value.)

Hebcal.holidays.Event.prototype.desc

An Array, either the array passed as desc, or the string passed, wrapped in an array. (Not actually a prototype value.)

Hebcal.holidays.Event.prototype.IGNORE_YEAR

This property is removed as of Hebcal JS 2.2.0.

Boolean, whether or not we ignore the year of the date. Always true for Gregorian dates. (Not actually a prototype value.)

Hebcal.holidays.Event.prototype.USER_EVENT

Hebcal.holidays.Event.prototype.LIGHT_CANDLES

Hebcal.holidays.Event.prototype.YOM_TOV_ENDS

Hebcal.holidays.Event.prototype.CHUL_ONLY

Hebcal.holidays.Event.prototype.IL_ONLY

Hebcal.holidays.Event.prototype.LIGHT_CANDLES_TZEIS

Booleans, whether or not the bitmasks for those values were provided. (Not actually prototype values.)

Hebcal.holidays.Event.prototype.is([date[, il]])

Returns a Boolean, whether or not the event applies for a given date.

date, if provided, can be a Hebcal.HDate or a Gregorian Date. If undefined, defaults to the current date.

il, if provided, should be a Boolean whether or not you are in Israel. If undefined, defaults to the value of Hebcal.holidays.Event.isIL. As of v2.2.0, il defaults to the il property of date.

Hebcal.holidays.Event.prototype.masks()

Returns a number representing the original bitmask passed to the constructor.

Hebcal.holidays.Event.prototype.getDesc(o)

Returns a string of the description. o can be one of the standard language strings.

Hebcal.holidays.Event.prototype.candleLighting()

Return a Date object representing the candle-lighting time for an event, if applicable. Otherwise, returns null.

The number of minutes before sunset can be customized with the Hebcal.holidays.Event.candleLighting property.

Hebcal.holidays.Event.prototype.havdalah()

Return a Date object representing the havdalah time for an event, if applicable. Otherwise, returns null.

The number of minutes after sunset can be customized with the Hebcal.holidays.Event.havdalah property.

Hebcal.holidays.Event.prototype.routine()

This property was added in v2.2.0.

Returns a Boolean, whether or not this is a "routine" event. Routine events are not included by default in Hebcal.HDate.prototype.holidays().

The default routine events are Shabbat and Erev Shabbat. This can be customized by changing the Hebcal.holidays.Event.prototype.routine.names array.

Hebcal.holidays.Event.isIL

Boolean, are we in Israel? Is not automatically set. Default false.

Hebcal.holidays.Event.candleLighting

The number of minutes before sunset to light candles. Defaults to 18.

Hebcal.holidays.Event.havdalah

The number of minutes after sunset to make havdalah. Defaults to 42. In v2.0, it defaulted to 50.

Hebcal.holidays.standards

Array of standard holidays that do not change based on years. Is used internally, and exported only incidentally.

This has been removed as of Hebcal JS 2.1.

Hebcal.holidays.getHolidaysForYear(year)

Returns an array of all holidays for the year, including variable ones. Is used internally, and exported only incidentally.

This has been removed as of Hebcal JS 2.1.

Hebcal.candleLighting

An alias of Hebcal.holidays.Event.candleLighting.

Hebcal.havdalah

An alias of Hebcal.holidays.Event.havdalah.

Hebcal.parshiot

An array of parsha names. Each item in the array is a description array (see intro). The second item is often null, so it is worthwhile to use Hebcal.LANGUAGE() to extract the names. This property was added in v2.1.

Hebcal.LANGUAGE(str, o)

Return a language from a string. o should be a standard options string. This is mostly internal, but can be useful with regards to Hebcal.parshiot (above), for listing parsha names in a certain language. This property was added in v2.1.

Hebcal.gematriya(string | num[, limit])

Return a gematriya string from a number, or a number from a string. Is imperfect above 1000.

The limit parameter can be a number, which is how many digits to truncate the original number to. Digits are removed from the beginning.

Hebcal.gematriya(5774, 3) === 'תשע"ד' // first converted to 774
Hebcal.gematriya(5774) === 'התשע"ד'
Hebcal.gematriya(5) === "ה'"
Hebcal.gematriya('התשע"ד') === 5774 // the ה before a high number means 5000
Hebcal.gematriya('ה"ד') === 9 // just adds them up
Hebcal.gematriya(1234) === 'תתררל"ד'

Hebcal.range(start, end[, step])

Return an array containing numbers between start and end, at an interval of step. Can be useful with find(), for fetching a bunch of days.

step defaults to 1 if not provided.

Hebcal.range(1, 10) // [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Hebcal.range(1, 10, 2) // [1, 3, 5, 7, 9]
Hebcal.range(15, 1, 3) // [15, 12, 9, 6, 3]
Hebcal.range(1, 2, 0.25) // [1, 1.25, 1.5, 1.75, 2]

Hebcal.map(object, mapFunc[, thisArg])

Similar to Array.prototype.map, but for objects.

Prior to v2.2, this function accepted a fourth argument, sameprops. It is now obsolete.

Hebcal.filter(object, filterFunc[, thisArg])

Similar to Array.prototype.filter, but for objects. filterFunc supports multiple types:

• Boolean: keep only truthy/falsey values
• Array: keep only those keys
• Function: test the function on each item of the object, passing it arguments val, index, object.

new Hebcal.Month(month, year)

This constructor contains information on a Hebrew month. It is not intended to be directly constructed, but it is fetched by Hebcal.prototype.getMonth(), so is useful to the end-user.

var month = new Hebcal.Month(7, 5774); // Tishrei
var month = new Hebcal.Month('Tishrei', 5774); // Tishrei

month can be a month name or number; year must be a number. An error is thrown if one of these conditions is not met.

Hebcal.Month.prototype.month

A number representing the month argument to the constructor. (Not actually a prototype value.)

Hebcal.Month.prototype.year

A number representing the year argument to the constructor. (Not actually a prototype value.)

Hebcal.Month.prototype.days

An array of days in the month. Each day is an instance of Hebcal.HDate. (Not actually a prototype value.)

Hebcal.Month.prototype.length

Number; the length of the month. Equivalent to the length of the days array. (Not actually a prototype value.)

Hebcal.Month.prototype.il

Boolean get/set. Whether or not the location is in Israel. Is usually set by the parent year. (Not actually a prototype value.)

Hebcal.Month.prototype.lat, Hebcal.Month.prototype.long

Number get/set. Latitude/Longitude of the location. Is usually set by the parent year. (Not actually prototype values.)

Hebcal.Month.prototype.__year

Internal, non-enumerable. A reference to the containing year. Only set if the month was created by a Hebcal(). (Not actually a prototype value.)

Hebcal.Month.prototype.isLeapYear()

Returns a Boolean, whether or not the year is a leap year.

Hebcal.Month.prototype.prev()

Returns a Hebcal.Month representing the previous month.

Hebcal.Month.prototype.next()

Returns a Hebcal.Month representing the following month.

Hebcal.Month.prototype.getDay(day)

Returns a Hebcal.HDate at a 1-based index in the month. Negative indices are from the end of the month.

Hebcal.Month.prototype.getYearObject()

Returns this.__year internal value.

As of v2.1, if it is "unaffiliated" (no __year), return a new Hebcal object.

Hebcal.Month.prototype.getName(o)

Returns a string with the name of the month. Takes a standard options string.

Hebcal.Month.prototype.rosh_chodesh()

Returns an array containing Hebcal.HDates for that month's Rosh Chodesh. Returns an array whether Rosh Chodesh is one or two days.

Hebcal.Month.prototype.map(mapFunc[, thisArg])

A shortcut for month.days.map(mapFunc, [thisArg]).

Hebcal.Month.prototype.molad()

Returns an object representing the Molad for the month. This method is new in v2.2.0.

The object returned has the following properties:

• doy - Number, from 0-6, with the day of week
• hour - Number, from 1-24, with the hour of the molad
• minutes - Number, from 0-59, with the minute
• chalakim - Number, from 0-17, with the chalakim of the minute
• day - Date, containing the exact time of the molad

Hebcal.Month.prototype.find(day)

A method similar to Hebcal.prototype.find() (see there), but specifically for a single month.

If day is a number, it is a 1-based index in the month. String, Hebcal.HDate, Date, and Array rules are the same as for Hebcal.prototype.find().

Default strings are:

• rosh_chodesh: Same as Hebcal.Month.prototype.rosh_chodesh()
• shabbat_mevarchim (aliased as shabbos_mevorchim): The last Shabbat in the month.

Strings are extensible in the same manner: Add a property of Hebcal.Month.prototype.find.strings. Name conversion rules and function context apply the same as with Hebcal.prototype.find().

find() returns an array of Hebcal.HDates.

This method is sometimes called by Hebcal.prototype.find().

new Hebcal.HDate([day[, month[, year]]])

An HDate represents a Hebrew date.

HDate supports multiple types.

If 0 arguments are passed, or only one is and it is undefined, return an HDate object representing the current date.

var day = new Hebcal.HDate();`

If 1 argument is passed:

• Gregorian Date: An HDate object representing that date.
  • Before v2.2: If the date is after sunset, it is the next day.
• HDate: Clone the object.
• String: Split the string by whitespace, and parse that.
• Number: Number of days since December 31, 1 BCE.

var day = new Hebcal.HDate(new Date(2014, 0, 1));
var day = new Hebcal.HDate('1 Tishrei 5774');
var day = new Hebcal.HDate('15 Adar 2 5774');

If 2: An HDate with the given day and month, and the current year.

var day = new Hebcal.HDate(15, 1); // Pesach
var day = new Hebcal.HDate("ו'", "סיון");

If 3: Numbers, or a month name for the second argument. Days and months are 1 based. If any values are out of range, e.g. the 31st of Nisan, convert them to proper values, i.e. 1st of Iyyar.

var day = new Hebcal.HDate(7, 2, 5770);
var day = new Hebcal.HDate(40, 'elul', 5773); // 11 Tishrei 5774

Hebcal.HDate will throw an error if bad arguments are passed.

The location will be set to Hebcal.defaultLocation.

Hebcal.HDate.prototype.year

Number. The year passed to the constructor, possibly fixed up. It is preferred to get this value with Hebcal.HDate.prototype.getFullYear(). (Not actually a prototype value.)

Hebcal.HDate.prototype.month

Number. The month passed to the constructor, possibly fixed up. It is preferred to get this value with Hebcal.HDate.prototype.getMonth(). (Not actually a prototype value.)

Hebcal.HDate.prototype.day

Number. The day passed to the constructor, possibly fixed up. It is preferred to get this value with Hebcal.HDate.prototype.getDate(). (Not actually a prototype value.)

Hebcal.HDate.prototype.lat

Hebcal.HDate.prototype.long

Numbers. The latitude/longitude of the location. These default to the values of Hebcal.defaultLocation. (Not actually prototype values.)

Hebcal.HDate.prototype.il

Boolean. Whether the current location is in Israel or not. This is relevant with regards to holidays. This gets set by Hebcal.defaultCity, and day.setCity(). It's possible that you may have to set it yourself in certain circumstances. (Not actually a prototype value.)

Hebcal.HDate.prototype.__month

Internal, non-enumerable. A reference to the containing month. Only set if the day was created by a Hebcal.Month(). (Not actually a prototype value.)

Hebcal.HDate.prototype.getFullYear()

Number. The year of the date.

Hebcal.HDate.prototype.getMonth()

Number. The month of the date. 1 is Nisan, 7 is Tishrei, 13 is Adar B.

Hebcal.HDate.prototype.getTishreiMonth()

Number. The Tishrei-based month of the date. 1 is Tishrei, 7 is Nisan, 13 is Elul in a leap year.

Hebcal.HDate.prototype.daysInMonth()

Number. The number of days in the month.

Hebcal.HDate.prototype.getDate()

Number. The day of the month of the date.

Hebcal.HDate.prototype.getDay()

Number. The day of the week of the date. 0 is Sunday, as with Date.prototype.getDay().

Hebcal.HDate.prototype.setFullYear(year)

Sets the year of the date. Returns the object it was called upon.

Hebcal.HDate.prototype.setMonth(month)

Sets the month of the date. Accepts a number or string. Returns the object it was called upon.

Hebcal.HDate.prototype.setTishreiMonth(month)

Sets the Tishrei-based month of the date. Returns the object it was called upon.

Hebcal.HDate.prototype.setDate(date)

Sets the day of the month of the date. Returns the object it was called upon.

Hebcal.HDate.prototype.greg()

Returns a Date object with the Gregorian date of the Hebrew date. The time is midnight.

Hebcal.HDate.prototype.gregEve()

Returns a Date object with the Gregorian date of the start of the Hebrew date, the previous evening. The time is sunset.

Hebcal.HDate.prototype.abs()

Return a number representing the number of days since December 31, 1 BCE, an "absolute date".

Hebcal.HDate.prototype.toString(o)

Return a string with the current day, month, and year. Takes a standard language options string.

new Hebcal.HDate().toString() // 16 Adar I 5774
new Hebcal.HDate(1,7,5769).toString() // 1 Tishrei 5769
new Hebcal.HDate(15,1,5773).toString('h') // ט"ו ניסן התשע"ג

Hebcal.HDate.prototype.getMonthName(o)

Return a string of the current month name. Takes a standard language options string.

Hebcal.HDate.prototype.getSedra(o)

Return an array of strings with the parshiot read on Shabbat, or a special event that takes precedence. Takes a standard language options string. Ashkenazis names for parshiot are not currently supported.

new Hebcal.HDate(24,12,5773).getSedra() // [ 'Vayakhel', 'Pekudei' ]
new Hebcal.HDate(18,1,5774).getSedra() // [ 'Chol hamoed Pesach' ]
new Hebcal.HDate(12,6,5774).getSedra() // [ 'Ki Tavo' ]
new Hebcal.HDate(15,7,5774).getSedra('a') // [ 'Chol hamoed Succos' ]
new Hebcal.HDate(19,12,5773).getSedra() // [ 'Ki Tisa' ]
new Hebcal.HDate(19,12,5773).getSedra('a') // [ 'Ki Tisa' ]
new Hebcal.HDate(8,8,5774).getSedra('h') // [ 'לך-לך' ]

Hebcal.HDate.prototype.getParsha(o)

An alias of getSedra(). Added v2.1.

Hebcal.HDate.prototype.isSedra()

Return a Boolean of whether the parsha is a regular parsha (true) or special chag reading (false). Added in v2.3.0.

new Hebcal.HDate(24,12,5773).isSedra() // true
new Hebcal.HDate(18,1,5774).isSedra() // false
new Hebcal.HDate(12,6,5774).isSedra() // true
new Hebcal.HDate(15,7,5774).isSedra() // false
new Hebcal.HDate(19,12,5773).isSedra() // true
new Hebcal.HDate(8,8,5774).isSedra() // true

Hebcal.HDate.prototype.isParsha()

An alias of isSedra(). Added v2.3.

Hebcal.HDate.prototype.setCity(city)

Set the location to the coordinates of a given city. For more about cities, see Hebcal.cities. Returns the object it was called upon.

Hebcal.HDate.prototype.setLocation(lat, long)

Set the location to the given coordinates. Returns the object it was called upon.

lat and long can be numbers, the coordinates in degrees, or arrays, [deg, mins].

Hebcal.HDate.prototype.sunrise()

Returns a Date with the sunrise time for the day. This is calculated based on the location. Please read the SunCalc disclaimer.

Hebcal.HDate.prototype.sunset()

Returns a Date with the sunset time for the day. This is calculated based on the location. Please read the SunCalc disclaimer.

Hebcal.HDate.prototype.hour()

Returns the number of milliseconds in a halachik hour (sha'a zmaniya). This is intended mostly for internal use.

Hebcal.HDate.prototype.hourMins()

Returns the number of minutes in a halachik hour (sha'a zmaniya). This is more useful for most people than milliseconds.

Hebcal.HDate.prototype.nightHour()

Returns the number of milliseconds in a halachik hour for the night. This is intended mostly for internal use.

Hebcal.HDate.prototype.nightHourMins()

Returns the number of minutes in a halachik hour for the night. This is more useful for most people than milliseconds.

Hebcal.HDate.prototype.getZemanim()

Returns an object containing halachik times (zemanim) for the day. Each property is a Date object. By default, these are:

• chatzot (calculated as sunrise + six hours)
• chatzot_night (calculated as sunset + six hours)
• alot_hashachar (calculated as when the sun is at -16.1 degrees, as per MyZmanim.com) (Before v2.2.0 it was called alot_hashacher. The misspelling is kept for backwards capability, but will be removed eventually.)
• misheyakir (calculated as when the sun is at -11.5 degrees, as per MyZmanim.com)
• misheyakir_machmir (calculated as when the sun is at -10.2 degrees, as per MyZmanim.com)
• neitz_hachama (the same as sunrise, but allows an event to be fired (added 2.1))
• sof_zman_shma (calculated as sunrise + 3 hours, according to the Gra and Baal HaTanya)
• sof_zman_tfilla (calculated as sunrise + 4 hours, according to the Gra and Baal HaTanya)
• mincha_gedola (calculated as sunrise + 6.5 hours)
• mincha_ketana (calculated as sunrise + 9.5 hours)
• plag_hamincha (calculated as sunrise + 10.75 hours)
• shkiah (the same as sunset, but allows an event to be fired (added 2.1))
• tzeit (calculated as when the sun is at -8.5 degrees, as per MyZmanim.com)

You can add a zeman to be returned with Hebcal.HDate.addZeman() (aliased as Hebcal.addZeman()).

Hebcal.HDate.prototype.candleLighting()

Return a Date object with the candle-lighting time for that day, or null if there is none. Added v2.2.0.

Hebcal.HDate.prototype.havdalah()

Return a Date object with the havdalah time for that day, or null if there is none. Added v2.2.0.

Hebcal.HDate.prototype.next()

Return tomorrow. Be patient, unless it's a second until sunset.

Just kidding. Returns an HDate representing the next day.

If part of a Hebcal() year, return the day from the year. Otherwise, return a new object. (The difference is mainly with location, and back-reference to the month/year).

Hebcal.HDate.prototype.prev()

Return yesterday. Or rather, an HDate representing the previous day.

If part of a Hebcal() year, return the day from the year. Otherwise, return a new object. (The difference is mainly with location, and back-reference to the month/year).

Hebcal.HDate.prototype.isSameDate(otherHDate)

Returns a Boolean whether or not the two dates represent the same day.

Hebcal.HDate.prototype.before(dayNumber)

Returns an HDate representing the last day dayNumber before the current date. Sunday is 0, Saturday 6.

new Hebcal.HDate(new Date('Wednesday February 19, 2014')).before(6).greg() // Sat Feb 15 2014

Hebcal.HDate.prototype.onOrBefore(dayNumber)

Returns an HDate representing the a dayNumber on or before the current date. Sunday is 0, Saturday 6. This property was added in Hebcal JS 2.1.

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

Hebcal.HDate.prototype.nearest(dayNumber)

Returns an HDate representing the nearest dayNumber to the current date. Sunday is 0, Saturday 6.

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

Hebcal.HDate.prototype.onOrAfter(dayNumber)

Returns an HDate representing the a dayNumber on or after the current date. Sunday is 0, Saturday 6.

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

Hebcal.HDate.prototype.after(dayNumber)

Returns an HDate representing the the first dayNumber after the current date. Sunday is 0, Saturday 6.

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

Hebcal.HDate.prototype.getMonthObject()

Return this.__month internal.

As of v2.1, if it is "unaffiliated" (no __month), return a new Hebcal.Month.

Hebcal.HDate.prototype.getYearObject()

Call getYearObject() of this.getMonthObject().

Hebcal.HDate.prototype.getGregMonthObject()

Return this.__gregmonth internal, or a new Hebcal.GregMonth. This method was added in Hebcal JS 2.1.

Hebcal.HDate.prototype.getGregYearObject()

Call getYearObject() of this.getGregMonthObject(). This method was added in Hebcal JS 2.1.

Hebcal.HDate.prototype.holidays(all)

Return an array containing Hebcal.holidays.Events applying to the current day.

The all argument was added in v2.2.0. If not included, it defaults to false. The action in prior versions is as if true was passed.

If all is not present, or is false, the function only returns events that apply to the current location, and omits "routine" events. For a definition of "routine", see Hebcal.holidays.Event.prototype.rotuine(). If all is present and is true, or using a version before 2.2.0, all events are returned, whether or not they are relevant.

Hebcal.HDate.prototype.omer()

Return a number representing the day of Sefirat Omer. Returns 0 if not during Sefirah.

new Hebcal.HDate(20, 'iyyar').omer() // 35
new Hebcal.HDate(16, 'nisan').omer() // 1
new Hebcal.HDate(15, 'nisan').omer() // 0

Hebcal.HDate.prototype.dafyomi(o)

Return a string containing the day's Daf Yomi. Takes a standard language options string.

new Hebcal.HDate(15, 'nisan', 5774).dafyomi() // Beitzah 16
new Hebcal.HDate(15, 'elul', 5772).dafyomi('a') // Berachos 30

Hebcal.HDate.prototype.tachanun()

Return a bitmask containing information on what Tachanun (or Tzidchatcha on Shabbat) is said on that day. For an explanation of how this works, see issue #38.

Tachanun is not said on Rosh Chodesh, the month of Nisan, Lag Baomer, Rosh Chodesh Sivan until Isru Chag, Tisha B'av, 15 Av, Erev Rosh Hashanah, Rosh Hashanah, Erev Yom Kippur until after Simchat Torah, Chanukah, Tu B'shvat, Purim and Shushan Purim, and Purim and Shushan Purim Katan.

In some congregations Tachanun is not said until from Rosh Chodesh Sivan until 14th Sivan, Sukkot until after Rosh Chodesh Cheshvan, Pesach Sheini, Yom Ha'atzmaut, and Yom Yerushalayim.

Tachanun is not said at Mincha on days before it is not said at Shacharit. Tachanun is not said at Shacharit on Shabbat, but is at Mincha, usually.

The bitmask is made up of the following values:

• 0 - No Tachanun, according to everybody
• 1 - Tachanun is said at Mincha
• 2 - Tachanun is said at Shacharit
• 4 - All congregations say Tachanun on the day

These bitmasks are also available as properties of the function:

• tachanun.NONE = 0
• tachanun.MINCHA = 1
• tachanun.SHACHARIT = 2
• tachanun.ALL_CONGS = 4

However, due to the lengthliness of typing Hebcal.HDate.prototype.tachanun.*BITMASK*, it may be easier to just use the values directly.

Hebcal.HDate.prototype.tachanun_uf()

New as of v2.2.4

Return a user-friendly representation of tachanun(). An object with Boolean properties {shacharit, mincha, all_congs}.

new Hebcal.HDate('1 Tishrei').tachanun_uf() // { shacharit: false, mincha: false, all_congs: false }
new Hebcal.HDate('25 Tishrei').tachanun_uf() // { shacharit: true, mincha: true, all_congs: false }
new Hebcal.HDate('6 Cheshvan').tachanun_uf() // { shacharit: true, mincha: true, all_congs: true }
new Hebcal.HDate().onOrAfter(5).tachanun_uf() // Friday: { shacharit: true, mincha: false, all_congs: true }
new Hebcal.HDate().onOrAfter(6).tachanun_uf() // Shabbat: { shacharit: false, mincha: true, all_congs: true }

Hebcal.HDate.prototype.hallel()

Return a number containing information on what Hallel is said on that day.

Whole Hallel is said on Chanukah, the first Yom Tov of Pesach, Shavuot, Sukkot, Yom Ha'atzmaut, and Yom Yerushalayim.

Half Hallel is said on Rosh Chodesh (not Rosh Hashanah), and the last 6 days of Pesach.

The number is one of the following values:

• 0 - No Hallel
• 1 - Half Hallel
• 2 - Whole Hallel

These values are also available as properties of the function:

• hallel.NONE = 0
• hallel.HALF = 1
• hallel.WHOLE = 2

However, due to the uncomfortableness of typing Hebcal.HDate.prototype.hallel.*BITMASK*, it may be easier to just use the values directly.

Hebcal.HDate.defaultLocation

An alias of Hebcal.defaultLocation.

Hebcal.HDate.defaultCity

An alias of Hebcal.defaultCity.

Hebcal.HDate.hebrew2abs(hdate)

Return an absolute date from an HDate. Equivalent to Hebcal.HDate.prototype.abs().

Obsolete in 2.1. Use HDate().abs().

Hebcal.HDate.abs2hebrew(absdate)

Return an HDate from absolute date. Equivalent to new Hebcal.HDate(absdate).

Obsolete in 2.1. Use new HDate().

Hebcal.HDate.addZeman(zeman, func)

Add a zeman to the object of times returned by Hebcal.HDate.prototype.getZemanim(). This function is aliased as Hebcal.addZeman().

zeman should be the name of the zeman; func should be a function taking one parameter, the HDate to get the zeman for. func should return a Date object with the time.

Hebcal.ready (client-side only)

Boolean; whether the geolocating code has completed or failed yet. If using the noloc script, it is always true.

Hebcal.onready() (client-side only, deprecated 2.1)

Set this to a function to be executed when geolocation has finished. Is called immediately upon being set in a no-loc environment.

This function is liable to be buggy.

This has been replaced as of Hebcal 2.1 with the ready event (see below). It will still work, but it is preferable not to use it.

Hebcal.events

A bunch of Hebcal-related events. This object is an instance of Node's events.EventEmitter. See there for methods.

Just a quick overview in case you don't feel like looking there right now:

Hebcal.events.on('locationChange', function(oldloc){
	console.log('moved from '+oldloc+' to '+Hebcal.defaultLocation);
});
Hebcal.events.removeListener('locationChange', Hebcal.events.listeners('locationChange')[0]);

This property is new in Hebcal 2.1.

Hebcal.events.refreshInterval

Number get/set. How often, in milliseconds, to check for zemanim and day changes. Upon being set, it updates the time of the interval. Defaults to 300000, which is 5 minutes. If set to 0, disables checking.

Hebcal.events.beforeZeman

Number. If it is under this number of milliseconds before a zeman, call the almostZeman event. Defaults to 600000, which is 10 minutes.

Hebcal.events.customs

Object of custom events, default empty. Each key in the object should be the name of a custom event, the property a Date object or UNIX timestamp number.

A custom event will be fired when the date reaches one of these times.

I figured that as long as i was building in time-based alerts, i could add this.

Events that can be emitted

ready (client-side only)

Fires when geolocating finished. If it is only set after geolocation finishes, all ready events are called then.

locationChange

Fires when the location is set using Hebcal.defaultLocation or Hebcal.defaultCity. WARNING: it does not fire when using Hebcal.HDate.defaultLocation or Hebcal.HDate.defaultCity.

dayChange

Fires at sunset. Sunset is calculated according to Hebcal.defaultLocation.

almostZeman(zeman, msUntil)

Fires when it is almost a zeman. Almost is if the current time is less than Hebcal.events.beforeZeman milliseconds until a zeman. Zemanim are calculated according to Hebcal.defaultLocation.

The callback function for this event is passed two parameters: the name of the zeman, and the number of milliseconds until it occurs (approximately).

atZeman(zeman)

Fires when the time is at a zeman. Zemanim are calculated according to Hebcal.defaultLocation. This is not precise; rather, it fires if there will not be another check before the zeman passes.

The callback function for this event is passed one parameter: the name of the zeman.

custom(time)

Fires when the time is at a custom breakpoint. This is not precise; rather, it fires if there will not be another check before the time passes.

The callback function for this event is passed one parameter: the name of the custom event.

new Hebcal.GregYear([year[, month]])

A constructor similar to new Hebcal(), but instead of being based on Hebrew years, GregYear is based on a Gregorian year. This property was added in Hebcal JS 2.1.

year, if provided, should be a number representing a Gregorian year, for example, 2014. If it is falsey (includes null, undefined, 0, false, etc), it defaults to the current year.

If it is a string, it can either be just a number with the year, or a year number and month. Anything that new Date() accepts works. For example, all of the following evaluate to February 2014: 2014-2, 2014 Feb, 2014/02, February 2014.

If it is not falsy, and not a number or string, Hebcal will throw an error.

month, if provided, supports multiple types:

• String -- The name of a single month.
• Number -- The number of a single month (January is 1)
• Array -- An array of either of the above two, or mixed. Basically, anything that can be passed to Hebcal.GregMonth (see below).

If not provided, it defaults to all of the months in the given year. If it is a different type, Hebcal will throw an error.

To get the full current year:

var gregyear = new Hebcal.GregYear();

Hebcal.GregYear.prototype.year

Number. The year passed to the constructor. (Not actually a prototype value.)

Hebcal.GregYear.prototype.months

Array of Hebcal.GregMonths. Is not intended to be used directly, but rather with the getMonth() and map() methods. (Not actually a prototype value.)

Hebcal.GregYear.prototype.hebyears

Array of numbers, which Hebrew years are in this Gregorian year. Only includes Hebrew years for the months passed.

Hebcal.GregYear.prototype.holidays

Array of holidays, as Hebcal.holidays.Events, for the represented year. Can be used directly. (Not actually a prototype value.)

Hebcal.GregYear.prototype.length

Number of days in the year. (Not actually a prototype value.)

Hebcal.GregYear.prototype.il

Boolean get/set. Whether the current location is in Israel or not. This is relevant with regards to holidays. This gets set by Hebcal.defaultCity, and gregyear.setCity(). It's possible that you may have to set it yourself in certain circumstances. (Not actually a prototype value.)

Hebcal.GregYear.prototype.lat and long

Number get/sets. The latitude and longitude of the current location. This is relevant with regards to getting times for dates. (Not actually prototype values.) Default: 0.

Hebcal.GregYear.prototype.isLeapYear()

Returns a Boolean, takes no arguments.

Hebcal.GregYear.prototype.setCity(city)

Functions exactly the same as Hebcal.prototype.setCity(city).

Hebcal.GregYear.prototype.setLocation(lat, long)

Functions exactly the same as Hebcal.prototype.setLocation(lat, long).

Hebcal.GregYear.prototype.next()

Return a Hebcal.GregYear for the following year. Takes 0 arguments.

Hebcal.GregYear.prototype.prev()

Return a Hebcal.GregYear for the preceding year. Takes 0 arguments.

Hebcal.GregYear.prototype.getMonth(month)

var jan = year.getMonth(1);
var dec = year.getMonth(-1);
var sept = year.getMonth('sept');
var nextJan = year.getMonth(13);

Takes a single argument, the month to get. Returns Hebcal.GregMonth representing the requested month.

If the month is a positive number, it is a month index. If the month is a negative number, it is a month index from the end of the year. If the month is a string, it should be a month name in English.

Hebcal.GregYear.prototype.days()

Functions exactly the same as Hebcal.prototype.days().

Hebcal.GregYear.prototype.map(mapFunc[, thisArg])

Functions exactly the same as Hebcal.prototype.map(mapFunc, thisArg).

Hebcal.GregYear.prototype.filter(filterFunc[, thisArg])

Functions exactly the same as Hebcal.prototype.filter(filterFunc, thisArg).

Hebcal.GregYear.prototype.addHoliday(event)

Functions exactly the same as Hebcal.prototype.addHoliday(event).

new Hebcal.GregMonth(month, year)

This constructor contains information on a Gregorian month. It is not intended to be directly constructed, but it is fetched by Hebcal.GregYear.prototype.getMonth(), so is useful to the end-user. This property was added in Hebcal JS 2.1.

var month = new Hebcal.Month(3, 2014); // March
var month = new Hebcal.Month('September', 2014); // September

month can be a month name or number; year must be a number. An error is thrown if one of these conditions is not met.

Hebcal.GregMonth.prototype.month

A number representing the month argument to the constructor. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.year

A number representing the year argument to the constructor. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.days

An array of days in the month. Each day is an instance of Hebcal.HDate. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.length

Number; the length of the month. Equivalent to the length of the days array. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.il

Boolean get/set. Whether or not the location is in Israel. Is usually set by the parent year. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.lat, Hebcal.GregMonth.prototype.long

Number get/set. Latitude/Longitude of the location. Is usually set by the parent year. (Not actually prototype values.)

Hebcal.GregMonth.prototype.__year

Internal, non-enumerable. A reference to the containing year. Only set if the month was created by a Hebcal.GregYear(). (Not actually a prototype value.)

Hebcal.GregMonth.prototype.hebmonths

Array of Hebrew months in the Gregorian month. Each item of the array is an object with properties month and year. (Not actually a prototype value.)

Hebcal.GregMonth.prototype.isLeapYear()

Returns a Boolean, whether or not the year is a leap year.

Hebcal.GregMonth.prototype.prev()

Returns a Hebcal.GregMonth representing the previous month.

Hebcal.GregMonth.prototype.next()

Returns a Hebcal.GregMonth representing the following month.

Hebcal.GregMonth.prototype.getDay(day)

Returns a Hebcal.HDate at a 1-based index in the month. Negative indices are from the end of the month.

Hebcal.GregMonth.prototype.getYearObject()

Returns this.__year internal value. If it is "unaffiliated" (no __year), return a new Hebcal.GregYear object.

Hebcal.GregMonth.prototype.getName()

Returns a string with the name of the month in English.

Hebcal.GregMonth.prototype.map(mapFunc[, thisArg])

A shortcut for month.days.map(mapFunc, [thisArg]).

Finale

That's it! You now know everything there is to know about Hebcal JavaScript! Good luck with whatever you choose to do with it!

If you have any other requests for features, just create an issue or even a pull request.