Package com.kosherjava.zmanim.hebrewcalendar

Class JewishDate

java.lang.Object
com.kosherjava.zmanim.hebrewcalendar.JewishDate
All Implemented Interfaces:
Cloneable, Comparable<JewishDate>
Direct Known Subclasses:
JewishCalendar
public class JewishDate extends Object implements Comparable<JewishDate>, Cloneable
The JewishDate is the base calendar class, that supports maintenance of a GregorianCalendar instance along with the corresponding Jewish date. This class can use the standard Java Date and Calendar classes for setting and maintaining the dates, but it does not subclass these classes or use them internally in any calculations. This class also does not have a concept of a time (which the Date class does). Please note that the calendar does not currently support dates prior to 1/1/1 Gregorian. Also keep in mind that the Gregorian calendar started on October 15, 1582, so any calculations prior to that are suspect (at least from a Gregorian perspective). While 1/1/1 Gregorian and forward are technically supported, any calculations prior to Hillel II's (Hakatan's) calendar (4119 in the Jewish Calendar / 359 CE Julian as recorded by Rav Hai Gaon) would be just an approximation. This open source Java code was written by Avrom Finkelstien from his C++ code. It was refactored to fit the KosherJava Zmanim API with simplification of the code, enhancements and some bug fixing. Some of Avrom's original C++ code was translated from C/C++ code in Calendrical Calculations by Nachum Dershowitz and Edward M. Reingold, Software-- Practice & Experience, vol. 20, no. 9 (September, 1990), pp. 899- 928. Any method with the mark "ND+ER" indicates that the method was taken from this source with minor modifications. If you are looking for a class that implements a Jewish calendar version of the Calendar class, one is available from the ICU (International Components for Unicode) project, formerly part of IBM's DeveloperWorks.
Author:
© Avrom Finkelstien 2002, © Eliyahu Hershfeld 2011 - 2021
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    ADAR
    Value of the month field indicating Adar (or Adar I in a leap year), the twelfth numeric month of the year in the Jewish calendar.
    static final int
    ADAR_II
    Value of the month field indicating Adar II, the leap (intercalary or embolismic) thirteenth (Undecimber) numeric month of the year added in Jewish leap year).
    static final int
    AV
    Value of the month field indicating Av, the fifth numeric month of the year in the Jewish calendar.
    private static final int
    CHALAKIM_MOLAD_TOHU
    Days from the beginning of Sunday till molad BaHaRaD.
    private static final int
    CHALAKIM_PER_DAY
    The number of chalakim (25,920) in a 24 hour day .
    private static final int
    CHALAKIM_PER_HOUR
    The number of chalakim (1080) in an hour.
    private static final int
    CHALAKIM_PER_MINUTE
    The number of chalakim (18) in a minute.
    private static final long
    CHALAKIM_PER_MONTH
    The number of chalakim in an average Jewish month.
    static final int
    CHASERIM
    A short year where both CHESHVAN and KISLEV are 29 days.
    static final int
    CHESHVAN
    Value of the month field indicating Cheshvan/marcheshvan, the eighth numeric month of the year in the Jewish calendar.
    private int
    dayOfWeek
    1 == Sunday, 2 == Monday, etc...
    static final int
    ELUL
    Value of the month field indicating Elul, the sixth numeric month of the year in the Jewish calendar.
    private int
    gregorianAbsDate
    Returns the absolute date (days since January 1, 0001 on the Gregorian calendar).
    private int
    gregorianDayOfMonth
    The day of the Gregorian month
    private int
    gregorianMonth
    The month, where 1 == January, 2 == February, etc...
    private int
    gregorianYear
    The Gregorian year
    static final int
    IYAR
    Value of the month field indicating Iyar, the second numeric month of the year in the Jewish calendar.
    private static final int
    JEWISH_EPOCH
    the Jewish epoch using the RD (Rata Die/Fixed Date or Reingold Dershowitz) day used in Calendrical Calculations.
    private int
    jewishDay
    the internal Jewish day.
    private int
    jewishMonth
    the internal Jewish month.
    private int
    jewishYear
    the internal Jewish year.
    static final int
    KESIDRAN
    An ordered year where CHESHVAN is 29 days and KISLEV is 30 days.
    static final int
    KISLEV
    Value of the month field indicating Kislev, the ninth numeric month of the year in the Jewish calendar.
    private int
    moladChalakim
    the internal count of molad chalakim.
    private int
    moladHours
    the internal count of molad hours.
    private int
    moladMinutes
    the internal count of molad minutes.
    static final int
    NISSAN
    Value of the month field indicating Nissan, the first numeric month of the year in the Jewish calendar.
    static final int
    SHELAIMIM
    A long year where both CHESHVAN and KISLEV are 30 days.
    static final int
    SHEVAT
    Value of the month field indicating Shevat, the eleventh numeric month of the year in the Jewish calendar.
    static final int
    SIVAN
    Value of the month field indicating Sivan, the third numeric month of the year in the Jewish calendar.
    static final int
    TAMMUZ
    Value of the month field indicating Tammuz, the fourth numeric month of the year in the Jewish calendar.
    static final int
    TEVES
    Value of the month field indicating Teves, the tenth numeric month of the year in the Jewish calendar.
    static final int
    TISHREI
    Value of the month field indicating Tishrei, the seventh numeric month of the year in the Jewish calendar.

  • Constructor Summary

    Constructors
    Constructor
    Description
    JewishDate()
    Default constructor will set a default date to the current system date.
    JewishDate(int jewishYear, int jewishMonth, int jewishDayOfMonth)
    Creates a Jewish date based on a Jewish year, month and day of month.
    JewishDate(long molad)
    Constructor that creates a JewishDate based on a molad passed in.
    JewishDate(LocalDate localDate)
    A constructor that initializes the date to the LocalDate paremeter.
    JewishDate(Calendar calendar)
    A constructor that initializes the date to the Calendar paremeter.
    JewishDate(Date date)
    A constructor that initializes the date to the Date paremeter.

  • Method Summary

    Modifier and Type
    Method
    Description
    private void
    absDateToDate(int absDate)
    Computes the Gregorian date from the absolute date.
    private void
    absDateToJewishDate()
    Computes the Jewish date from the absolute date.
    private static int
    addDechiyos(int year, int moladDay, int moladParts)
    Adds the 4 dechiyos for molad Tishrei.
    void
    back()
    Rolls the date back by 1 day.
    Object
    clone()
    A method that creates a deep copy of the object.
    int
    compareTo(JewishDate jewishDate)
    Compares two dates as per the compareTo() method in the Comparable interface.
    boolean
    equals(Object object)
    Indicates whether some other object is "equal to" this one.
    void
    forward(int field, int amount)
    Rolls the date, month or year forward by the amount passed in.
    private void
    forwardJewishMonth(int amount)
    Forward the Jewish date by the number of months passed in.
    int
    getAbsDate()
    Returns the absolute date (days since January 1, 0001 on the Gregorian calendar).
    long
    getChalakimSinceMoladTohu()
    Returns the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu to the Jewish year and month that this Object is set to.
    private static long
    getChalakimSinceMoladTohu(int year, int month)
    Returns the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu to the year and month passed in.
    int
    getCheshvanKislevKviah()
    Returns the Cheshvan and Kislev kviah (whether a Jewish year is short, regular or long).
    int
    getDayOfWeek()
    Returns the day of the week as a number between 1-7.
    int
    getDaysInJewishMonth()
    Returns the number of days of the Jewish month that the calendar is currently set to.
    private static int
    getDaysInJewishMonth(int month, int year)
    Returns the number of days of a Jewish month for a given month and year.
    int
    getDaysInJewishYear()
    Returns the number of days for the current year that the calendar is set to.
    static int
    getDaysInJewishYear(int year)
    Returns the number of days for a given Jewish year.
    int
    getDaysSinceStartOfJewishYear()
    returns the number of days from Rosh Hashana of the date passed in, to the full date passed in.
    private static int
    getDaysSinceStartOfJewishYear(int year, int month, int dayOfMonth)
    returns the number of days from Rosh Hashana of the date passed in, to the full date passed in.
    Calendar
    getGregorianCalendar()
    Returns this object's date as a Calendar object.
    int
    getGregorianDayOfMonth()
    Returns the Gregorian day of the month.
    int
    getGregorianMonth()
    Returns the Gregorian month (between 0-11).
    int
    getGregorianYear()
    Returns the Gregotian year.
    static int
    getJewishCalendarElapsedDays(int year)
    Returns the number of days elapsed from the Sunday prior to the start of the Jewish calendar to the mean conjunction of Tishri of the Jewish year.
    int
    getJewishDayOfMonth()
    Returns the Jewish day of month.
    int
    getJewishMonth()
    Returns the Jewish month 1-12 (or 13 years in a leap year).
    private static int
    getJewishMonthOfYear(int year, int month)
    Converts the NISSAN based constants used by this class to numeric month starting from TISHREI.
    int
    getJewishYear()
    Returns the Jewish year.
    (package private) int
    getLastDayOfGregorianMonth(int month)
    Returns the last day in a gregorian month
    private static int
    getLastDayOfGregorianMonth(int month, int year)
    Returns the number of days in a given month in a given month and year.
    private static int
    getLastMonthOfJewishYear(int year)
    Returns the last month of a given Jewish year.
    LocalDate
    getLocalDate()
    Returns this object's date as a LocalDate object.
    JewishDate
    getMolad()
    Returns the molad for a given year and month.
    int
    getMoladChalakim()
    Returns the molad chalakim/parts.
    int
    getMoladHours()
    Returns the molad hours.
    int
    getMoladMinutes()
    Returns the molad minutes.
    private static int
    gregorianDateToAbsDate(int year, int month, int dayOfMonth)
    Computes the absolute date from a Gregorian date.
    int
    hashCode()
    Overrides Object.hashCode().
    boolean
    isCheshvanLong()
    Returns if Cheshvan is long (30 days VS 29 days) for the current year that the calendar is set to.
    private static boolean
    isCheshvanLong(int year)
    Returns if Cheshvan is long in a given Jewish year.
    (package private) boolean
    isGregorianLeapYear(int year)
    Returns is the year passed in is a Gregorian leap year.
    boolean
    isJewishLeapYear()
    Returns if the year the calendar is set to is a Jewish leap year.
    private static boolean
    isJewishLeapYear(int year)
    Returns if the year is a Jewish leap year.
    boolean
    isKislevShort()
    Returns if the Kislev is short for the year that this class is set to.
    private static boolean
    isKislevShort(int year)
    Returns if Kislev is short (29 days VS 30 days) in a given Jewish year.
    private static int
    jewishDateToAbsDate(int year, int month, int dayOfMonth)
    Returns the absolute date of Jewish date.
    private static int
    moladToAbsDate(long chalakim)
    Returns the number of days from the Jewish epoch from the number of chalakim from the epoch passed in.
    void
    resetDate()
    Resets this date to the current system date.
    void
    setDate(LocalDate localDate)
    Sets the date based on a LocalDate object.
    void
    setDate(Calendar calendar)
    Sets the date based on a Calendar object.
    void
    setDate(Date date)
    Sets the date based on a Date object.
    void
    setGregorianDate(int year, int month, int dayOfMonth)
    Sets the Gregorian Date, and updates the Jewish date accordingly.
    void
    setGregorianDayOfMonth(int dayOfMonth)
    sets the Gregorian Day of month.
    void
    setGregorianMonth(int month)
    Sets the Gregorian month.
    void
    setGregorianYear(int year)
    sets the Gregorian year.
    private void
    setInternalGregorianDate(int year, int month, int dayOfMonth)
    Sets the hidden internal representation of the Gregorian date , and updates the Jewish date accordingly.
    void
    setJewishDate(int year, int month, int dayOfMonth)
    Sets the Jewish Date and updates the Gregorian date accordingly.
    void
    setJewishDate(int year, int month, int dayOfMonth, int hours, int minutes, int chalakim)
    Sets the Jewish Date and updates the Gregorian date accordingly.
    void
    setJewishDayOfMonth(int dayOfMonth)
    sets the Jewish day of month.
    void
    setJewishMonth(int month)
    sets the Jewish month.
    void
    setJewishYear(int year)
    sets the Jewish year.
    void
    setMoladChalakim(int moladChalakim)
    Sets the molad chalakim/parts.
    void
    setMoladHours(int moladHours)
    Sets the molad hours.
    void
    setMoladMinutes(int moladMinutes)
    Sets the molad minutes.
    private void
    setMoladTime(int chalakim)
    Sets the molad time (hours minutes and chalakim) based on the number of chalakim since the start of the day.
    String
    toString()
    Returns a string containing the Jewish date in the form, "day Month, year" e.g. "21 Shevat, 5729".
    private static void
    validateGregorianDate(int year, int month, int dayOfMonth)
    Validates the components of a Gregorian date for validity.
    private static void
    validateGregorianDayOfMonth(int dayOfMonth)
    Validates a Gregorian day of month for validity.
    private static void
    validateGregorianMonth(int month)
    Validates a Gregorian month for validity.
    private static void
    validateGregorianYear(int year)
    Validates a Gregorian year for validity.
    private static void
    validateJewishDate(int year, int month, int dayOfMonth, int hours, int minutes, int chalakim)
    Validates the components of a Jewish date for validity.

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • NISSAN

      public static final int NISSAN
      Value of the month field indicating Nissan, the first numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 7th (or 8th in a leap year) month of the year.
      See Also:

    • IYAR

      public static final int IYAR
      Value of the month field indicating Iyar, the second numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 8th (or 9th in a leap year) month of the year.
      See Also:

    • SIVAN

      public static final int SIVAN
      Value of the month field indicating Sivan, the third numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 9th (or 10th in a leap year) month of the year.
      See Also:

    • TAMMUZ

      public static final int TAMMUZ
      Value of the month field indicating Tammuz, the fourth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 10th (or 11th in a leap year) month of the year.
      See Also:

    • AV

      public static final int AV
      Value of the month field indicating Av, the fifth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 11th (or 12th in a leap year) month of the year.
      See Also:

    • ELUL

      public static final int ELUL
      Value of the month field indicating Elul, the sixth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 12th (or 13th in a leap year) month of the year.
      See Also:

    • TISHREI

      public static final int TISHREI
      Value of the month field indicating Tishrei, the seventh numeric month of the year in the Jewish calendar. With the year starting at this month, it would actually be the 1st month of the year.
      See Also:

    • CHESHVAN

      public static final int CHESHVAN
      Value of the month field indicating Cheshvan/marcheshvan, the eighth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 2nd month of the year.
      See Also:

    • KISLEV

      public static final int KISLEV
      Value of the month field indicating Kislev, the ninth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 3rd month of the year.
      See Also:

    • TEVES

      public static final int TEVES
      Value of the month field indicating Teves, the tenth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 4th month of the year.
      See Also:

    • SHEVAT

      public static final int SHEVAT
      Value of the month field indicating Shevat, the eleventh numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 5th month of the year.
      See Also:

    • ADAR

      public static final int ADAR
      Value of the month field indicating Adar (or Adar I in a leap year), the twelfth numeric month of the year in the Jewish calendar. With the year starting at TISHREI, it would actually be the 6th month of the year.
      See Also:

    • ADAR_II

      public static final int ADAR_II
      Value of the month field indicating Adar II, the leap (intercalary or embolismic) thirteenth (Undecimber) numeric month of the year added in Jewish leap year). The leap years are years 3, 6, 8, 11, 14, 17 and 19 of a 19 year cycle. With the year starting at TISHREI, it would actually be the 7th month of the year.
      See Also:

    • JEWISH_EPOCH

      private static final int JEWISH_EPOCH
      the Jewish epoch using the RD (Rata Die/Fixed Date or Reingold Dershowitz) day used in Calendrical Calculations. Day 1 is January 1, 0001 Gregorian
      See Also:

    • CHALAKIM_PER_MINUTE

      private static final int CHALAKIM_PER_MINUTE
      The number of chalakim (18) in a minute.
      See Also:

    • CHALAKIM_PER_HOUR

      private static final int CHALAKIM_PER_HOUR
      The number of chalakim (1080) in an hour.
      See Also:

    • CHALAKIM_PER_DAY

      private static final int CHALAKIM_PER_DAY
      The number of chalakim (25,920) in a 24 hour day .
      See Also:

    • CHALAKIM_PER_MONTH

      private static final long CHALAKIM_PER_MONTH
      The number of chalakim in an average Jewish month. A month has 29 days, 12 hours and 793 chalakim (44 minutes and 3.3 seconds) for a total of 765,433 chalakim
      See Also:

    • CHALAKIM_MOLAD_TOHU

      private static final int CHALAKIM_MOLAD_TOHU
      Days from the beginning of Sunday till molad BaHaRaD. Calculated as 1 day, 5 hours and 204 chalakim = (24 + 5) * 1080 + 204 = 31524
      See Also:

    • CHASERIM

      public static final int CHASERIM
      A short year where both CHESHVAN and KISLEV are 29 days.
      See Also:

    • KESIDRAN

      public static final int KESIDRAN
      An ordered year where CHESHVAN is 29 days and KISLEV is 30 days.
      See Also:

    • SHELAIMIM

      public static final int SHELAIMIM
      A long year where both CHESHVAN and KISLEV are 30 days.
      See Also:

    • jewishMonth

      private int jewishMonth
      the internal Jewish month.

    • jewishDay

      private int jewishDay
      the internal Jewish day.

    • jewishYear

      private int jewishYear
      the internal Jewish year.

    • moladHours

      private int moladHours
      the internal count of molad hours.

    • moladMinutes

      private int moladMinutes
      the internal count of molad minutes.

    • moladChalakim

      private int moladChalakim
      the internal count of molad chalakim.

    • gregorianMonth

      private int gregorianMonth
      The month, where 1 == January, 2 == February, etc... Note that this is different than the Java's Calendar class where January ==0

    • gregorianDayOfMonth

      private int gregorianDayOfMonth
      The day of the Gregorian month

    • gregorianYear

      private int gregorianYear
      The Gregorian year

    • dayOfWeek

      private int dayOfWeek
      1 == Sunday, 2 == Monday, etc...

    • gregorianAbsDate

      private int gregorianAbsDate
      Returns the absolute date (days since January 1, 0001 on the Gregorian calendar).
      See Also:

  • Constructor Details

    • JewishDate

      public JewishDate(long molad)
      Constructor that creates a JewishDate based on a molad passed in. The molad would be the number of chalakim/parts starting at the beginning of Sunday prior to the molad Tohu BeHaRaD (Be = Monday, Ha= 5 hours and Rad =204 chalakim/parts) - prior to the start of the Jewish calendar. BeHaRaD is 23:11:20 on Sunday night(5 hours 204/1080 chalakim after sunset on Sunday evening).
      Parameters:
      molad - the number of chalakim since the beginning of Sunday prior to BaHaRaD

    • JewishDate

      public JewishDate(int jewishYear, int jewishMonth, int jewishDayOfMonth)
      Creates a Jewish date based on a Jewish year, month and day of month.
      Parameters:
      jewishYear - the Jewish year
      jewishMonth - the Jewish month. The method expects a 1 for Nissan ... 12 for Adar and 13 for Adar II. Use the constants NISSAN ... ADAR (or ADAR_II for a leap year Adar II) to avoid any confusion.
      jewishDayOfMonth - the Jewish day of month. If 30 is passed in for a month with only 29 days (for example IYAR, or KISLEV in a year that isKislevShort()), the 29th (last valid date of the month) will be set
      Throws:
      IllegalArgumentException - if the day of month is < 1 or > 30, or a year of < 0 is passed in.

    • JewishDate

      public JewishDate()
      Default constructor will set a default date to the current system date.

    • JewishDate

      public JewishDate(Date date)
      A constructor that initializes the date to the Date paremeter.
      Parameters:
      date - the Date to set the calendar to
      Throws:
      IllegalArgumentException - if the date would fall prior to the January 1, 1 AD

    • JewishDate

      public JewishDate(Calendar calendar)
      A constructor that initializes the date to the Calendar paremeter.
      Parameters:
      calendar - the Calendar to set the calendar to
      Throws:
      IllegalArgumentException - if the Calendar.ERA is GregorianCalendar.BC

    • JewishDate

      public JewishDate(LocalDate localDate)
      A constructor that initializes the date to the LocalDate paremeter.
      Parameters:
      localDate - the LocalDate to set the calendar to
      Throws:
      IllegalArgumentException - if the Calendar.ERA is GregorianCalendar.BC

  • Method Details

    • getMoladHours

      public int getMoladHours()
      Returns the molad hours. Only a JewishDate object populated with getMolad(), setJewishDate(int, int, int, int, int, int) or setMoladHours(int) will have this field populated. A regular JewishDate object will have this field set to 0.
      Returns:
      the molad hours
      See Also:

    • setMoladHours

      public void setMoladHours(int moladHours)
      Sets the molad hours.
      Parameters:
      moladHours - the molad hours to set
      See Also:

    • getMoladMinutes

      public int getMoladMinutes()
      Returns the molad minutes. Only an object populated with getMolad(), setJewishDate(int, int, int, int, int, int) or or setMoladMinutes(int) will have these fields populated. A regular JewishDate object will have this field set to 0.
      Returns:
      the molad minutes
      See Also:

    • setMoladMinutes

      public void setMoladMinutes(int moladMinutes)
      Sets the molad minutes. The expectation is that the traditional minute-less chalakim will be broken out to minutes and chalakim/parts , so 793 (TaShTZaG) parts would have the minutes set to 44 and chalakim to 1.
      Parameters:
      moladMinutes - the molad minutes to set
      See Also:

    • setMoladChalakim

      public void setMoladChalakim(int moladChalakim)
      Sets the molad chalakim/parts. The expectation is that the traditional minute-less chalakim will be broken out to minutes and chalakim, so 793 (TaShTZaG) parts would have the minutes set to 44 and chalakim to 1.
      Parameters:
      moladChalakim - the molad chalakim/parts to set
      See Also:

    • getMoladChalakim

      public int getMoladChalakim()
      Returns the molad chalakim/parts. Only an object populated with getMolad(), setJewishDate(int, int, int, int, int, int) or or setMoladChalakim(int) will have these fields populated. A regular JewishDate object will have this field set to 0.
      Returns:
      the molad chalakim/parts
      See Also:

    • getLastDayOfGregorianMonth

      int getLastDayOfGregorianMonth(int month)
      Returns the last day in a gregorian month
      Parameters:
      month - the Gregorian month
      Returns:
      the last day of the Gregorian month

    • isGregorianLeapYear

      boolean isGregorianLeapYear(int year)
      Returns is the year passed in is a Gregorian leap year.
      Parameters:
      year - the Gregorian year
      Returns:
      if the year in question is a leap year.

    • getLastDayOfGregorianMonth

      private static int getLastDayOfGregorianMonth(int month, int year)
      Returns the number of days in a given month in a given month and year.
      Parameters:
      month - the month. As with other cases in this class, this is 1-based, not zero-based.
      year - the year (only impacts February)
      Returns:
      the number of days in the month in the given year

    • absDateToDate

      private void absDateToDate(int absDate)
      Computes the Gregorian date from the absolute date. ND+ER
      Parameters:
      absDate - the absolute date

    • getAbsDate

      public int getAbsDate()
      Returns the absolute date (days since January 1, 0001 on the Gregorian calendar).
      Returns:
      the number of days since January 1, 1

    • gregorianDateToAbsDate

      private static int gregorianDateToAbsDate(int year, int month, int dayOfMonth)
      Computes the absolute date from a Gregorian date. ND+ER
      Parameters:
      year - the Gregorian year
      month - the Gregorian month. Unlike the Java Calendar where January has the value of 0,This expects a 1 for January
      dayOfMonth - the day of the month (1st, 2nd, etc...)
      Returns:
      the absolute Gregorian day

    • isJewishLeapYear

      private static boolean isJewishLeapYear(int year)
      Returns if the year is a Jewish leap year. Years 3, 6, 8, 11, 14, 17 and 19 in the 19 year cycle are leap years.
      Parameters:
      year - the Jewish year.
      Returns:
      true if it is a leap year
      See Also:

    • isJewishLeapYear

      public boolean isJewishLeapYear()
      Returns if the year the calendar is set to is a Jewish leap year. Years 3, 6, 8, 11, 14, 17 and 19 in the 19 year cycle are leap years.
      Returns:
      true if it is a leap year
      See Also:

    • getLastMonthOfJewishYear

      private static int getLastMonthOfJewishYear(int year)
      Returns the last month of a given Jewish year. This will be 12 on a non leap year or 13 on a leap year.
      Parameters:
      year - the Jewish year.
      Returns:
      12 on a non leap year or 13 on a leap year
      See Also:

    • getJewishCalendarElapsedDays

      public static int getJewishCalendarElapsedDays(int year)
      Returns the number of days elapsed from the Sunday prior to the start of the Jewish calendar to the mean conjunction of Tishri of the Jewish year.
      Parameters:
      year - the Jewish year
      Returns:
      the number of days elapsed from prior to the molad Tohu BaHaRaD (Be = Monday, Ha= 5 hours and Rad =204 chalakim/parts) prior to the start of the Jewish calendar, to the mean conjunction of Tishri of the Jewish year. BeHaRaD is 23:11:20 on Sunday night(5 hours 204/1080 chalakim after sunset on Sunday evening).

    • addDechiyos

      private static int addDechiyos(int year, int moladDay, int moladParts)
      Adds the 4 dechiyos for molad Tishrei. These are:
      1. Lo ADU Rosh - Rosh Hashana can't fall on a Sunday, Wednesday or Friday. If the molad fell on one of these days, Rosh Hashana is delayed to the following day.
      2. Molad Zaken - If the molad of Tishrei falls after 12 noon, Rosh Hashana is delayed to the following day. If the following day is ADU, it will be delayed an additional day.
      3. GaTRaD - If on a non leap year the molad of Tishrei falls on a Tuesday (Ga) on or after 9 hours (T) and 204 chalakim (TRaD) it is delayed till Thursday (one day delay, plus one day for Lo ADU Rosh)
      4. BeTuTaKFoT - if the year following a leap year falls on a Monday (Be) on or after 15 hours (Tu) and 589 chalakim (TaKFoT) it is delayed till Tuesday
      Parameters:
      year - the year
      moladDay - the molad day
      moladParts - the molad parts
      Returns:
      the number of elapsed days in the JewishCalendar adjusted for the 4 dechiyos.

    • getChalakimSinceMoladTohu

      private static long getChalakimSinceMoladTohu(int year, int month)
      Returns the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu to the year and month passed in.
      Parameters:
      year - the Jewish year
      month - the Jewish month the Jewish month, with the month numbers starting from Nisan. Use the JewishDate constants such as TISHREI.
      Returns:
      the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu

    • getChalakimSinceMoladTohu

      public long getChalakimSinceMoladTohu()
      Returns the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu to the Jewish year and month that this Object is set to.
      Returns:
      the number of chalakim (parts - 1080 to the hour) from the original hypothetical Molad Tohu

    • getJewishMonthOfYear

      private static int getJewishMonthOfYear(int year, int month)
      Converts the NISSAN based constants used by this class to numeric month starting from TISHREI. This is required for Molad claculations.
      Parameters:
      year - The Jewish year
      month - The Jewish Month
      Returns:
      the Jewish month of the year starting with Tishrei

    • validateJewishDate

      private static void validateJewishDate(int year, int month, int dayOfMonth, int hours, int minutes, int chalakim)
      Validates the components of a Jewish date for validity. It will throw an IllegalArgumentException if the Jewish date is earlier than 18 Teves, 3761 (1/1/1 Gregorian), a month < 1 or > 12 (or 13 on a leap year), the day of month is < 1 or > 30, an hour < 0 or > 23, a minute < 0 or > 59 or chalakim < 0 or > 17. For larger a larger number of chalakim such as 793 (TaShTzaG) break the chalakim into minutes (18 chalakim per minutes, so it would be 44 minutes and 1 chelek in the case of 793/TaShTzaG).
      Parameters:
      year - the Jewish year to validate. It will reject any year <= 3761 (lower than the year 1 Gregorian).
      month - the Jewish month to validate. It will reject a month < 1 or > 12 (or 13 on a leap year) .
      dayOfMonth - the day of the Jewish month to validate. It will reject any value < 1 or > 30 TODO: check calling methods to see if there is any reason that the class can validate that 30 is invalid for some months.
      hours - the hours (for molad calculations). It will reject an hour < 0 or > 23
      minutes - the minutes (for molad calculations). It will reject a minute < 0 or > 59
      chalakim - the chalakim/parts (for molad calculations). It will reject a chalakim < 0 or > 17. For larger numbers such as 793 (TaShTzaG) break the chalakim into minutes (18 chalakim per minutes, so it would be 44 minutes and 1 chelek in the case of 793/TaShTzaG)
      Throws:
      IllegalArgumentException - if a A Jewish date earlier than 18 Teves, 3761 (1/1/1 Gregorian), a month < 1 or > 12 (or 13 on a leap year), the day of month is < 1 or > 30, an hour < 0 or > 23, a minute < 0 or > 59 or chalakim < 0 or > 17. For larger a larger number of chalakim such as 793 (TaShTzaG) break the chalakim into minutes (18 chalakim per minutes, so it would be 44 minutes and 1 chelek in the case of 793 (TaShTzaG).

    • validateGregorianDate

      private static void validateGregorianDate(int year, int month, int dayOfMonth)
      Validates the components of a Gregorian date for validity. It will throw an IllegalArgumentException if a year of < 1, a month < 0 or > 11 or a day of month < 1 is passed in.
      Parameters:
      year - the Gregorian year to validate. It will reject any year < 1.
      month - the Gregorian month number to validate. It will enforce that the month is between 0 - 11 like a GregorianCalendar, where Calendar.JANUARY has a value of 0.
      dayOfMonth - the day of the Gregorian month to validate. It will reject any value < 1, but will allow values > 31 since calling methods will simply set it to the maximum for that month. TODO: check calling methods to see if there is any reason that the class needs days > the maximum.
      Throws:
      IllegalArgumentException - if a year of < 1, a month < 0 or > 11 or a day of month < 1 is passed in
      See Also:

    • validateGregorianMonth

      private static void validateGregorianMonth(int month)
      Validates a Gregorian month for validity.
      Parameters:
      month - the Gregorian month number to validate. It will enforce that the month is between 0 - 11 like a GregorianCalendar, where Calendar.JANUARY has a value of 0.

    • validateGregorianDayOfMonth

      private static void validateGregorianDayOfMonth(int dayOfMonth)
      Validates a Gregorian day of month for validity.
      Parameters:
      dayOfMonth - the day of the Gregorian month to validate. It will reject any value < 1, but will allow values > 31 since calling methods will simply set it to the maximum for that month. TODO: check calling methods to see if there is any reason that the class needs days > the maximum.

    • validateGregorianYear

      private static void validateGregorianYear(int year)
      Validates a Gregorian year for validity.
      Parameters:
      year - the Gregorian year to validate. It will reject any year < 1.

    • getDaysInJewishYear

      public static int getDaysInJewishYear(int year)
      Returns the number of days for a given Jewish year. ND+ER
      Parameters:
      year - the Jewish year
      Returns:
      the number of days for a given Jewish year.
      See Also:

    • getDaysInJewishYear

      public int getDaysInJewishYear()
      Returns the number of days for the current year that the calendar is set to.
      Returns:
      the number of days for the Object's current Jewish year.
      See Also:

    • isCheshvanLong

      private static boolean isCheshvanLong(int year)
      Returns if Cheshvan is long in a given Jewish year. The method name isLong is done since in a Kesidran (ordered) year Cheshvan is short. ND+ER
      Parameters:
      year - the year
      Returns:
      true if Cheshvan is long in Jewish year.
      See Also:

    • isCheshvanLong

      public boolean isCheshvanLong()
      Returns if Cheshvan is long (30 days VS 29 days) for the current year that the calendar is set to. The method name isLong is done since in a Kesidran (ordered) year Cheshvan is short.
      Returns:
      true if Cheshvan is long for the current year that the calendar is set to
      See Also:

    • isKislevShort

      private static boolean isKislevShort(int year)
      Returns if Kislev is short (29 days VS 30 days) in a given Jewish year. The method name isShort is done since in a Kesidran (ordered) year Kislev is long. ND+ER
      Parameters:
      year - the Jewish year
      Returns:
      true if Kislev is short for the given Jewish year.
      See Also:

    • isKislevShort

      public boolean isKislevShort()
      Returns if the Kislev is short for the year that this class is set to. The method name isShort is done since in a Kesidran (ordered) year Kislev is long.
      Returns:
      true if Kislev is short for the year that this class is set to

    • getCheshvanKislevKviah

      public int getCheshvanKislevKviah()
      Returns the Cheshvan and Kislev kviah (whether a Jewish year is short, regular or long). It will return SHELAIMIM if both cheshvan and kislev are 30 days, KESIDRAN if Cheshvan is 29 days and Kislev is 30 days and CHASERIM if both are 29 days.
      Returns:
      SHELAIMIM if both cheshvan and kislev are 30 days, KESIDRAN if Cheshvan is 29 days and Kislev is 30 days and CHASERIM if both are 29 days.
      See Also:

    • getDaysInJewishMonth

      private static int getDaysInJewishMonth(int month, int year)
      Returns the number of days of a Jewish month for a given month and year.
      Parameters:
      month - the Jewish month
      year - the Jewish Year
      Returns:
      the number of days for a given Jewish month

    • getDaysInJewishMonth

      public int getDaysInJewishMonth()
      Returns the number of days of the Jewish month that the calendar is currently set to.
      Returns:
      the number of days for the Jewish month that the calendar is currently set to.

    • absDateToJewishDate

      private void absDateToJewishDate()
      Computes the Jewish date from the absolute date.

    • jewishDateToAbsDate

      private static int jewishDateToAbsDate(int year, int month, int dayOfMonth)
      Returns the absolute date of Jewish date. ND+ER
      Parameters:
      year - the Jewish year. The year can't be negative
      month - the Jewish month starting with Nisan. Nisan expects a value of 1 etc till Adar with a value of 12. For a leap year, 13 will be the expected value for Adar II. Use the constants NISSAN etc.
      dayOfMonth - the Jewish day of month. valid values are 1-30. If the day of month is set to 30 for a month that only has 29 days, the day will be set as 29.
      Returns:
      the absolute date of the Jewish date.

    • getMolad

      public JewishDate getMolad()
      Returns the molad for a given year and month. Returns a JewishDate Object set to the date of the molad with the hours, minutes and chalakim set. In the current implementation, it sets the molad time based on a midnight date rollover. This means that Rosh Chodesh Adar II, 5771 with a molad of 7 chalakim past midnight on Shabbos 29 Adar I / March 5, 2011 12:00 AM and 7 chalakim, will have the following values: hours: 0, minutes: 0, Chalakim: 7.
      Returns:
      a JewishDate Object set to the date of the molad with the hours, minutes and chalakim set.

    • moladToAbsDate

      private static int moladToAbsDate(long chalakim)
      Returns the number of days from the Jewish epoch from the number of chalakim from the epoch passed in.
      Parameters:
      chalakim - the number of chalakim since the beginning of Sunday prior to BaHaRaD
      Returns:
      the number of days from the Jewish epoch

    • setMoladTime

      private void setMoladTime(int chalakim)
      Sets the molad time (hours minutes and chalakim) based on the number of chalakim since the start of the day.
      Parameters:
      chalakim - the number of chalakim since the start of the day.

    • getDaysSinceStartOfJewishYear

      private static int getDaysSinceStartOfJewishYear(int year, int month, int dayOfMonth)
      returns the number of days from Rosh Hashana of the date passed in, to the full date passed in.
      Parameters:
      year - the Jewish year
      month - the Jewish month
      dayOfMonth - the day in the Jewish month
      Returns:
      the number of days

    • getDaysSinceStartOfJewishYear

      public int getDaysSinceStartOfJewishYear()
      returns the number of days from Rosh Hashana of the date passed in, to the full date passed in.
      Returns:
      the number of days

    • setDate

      public void setDate(Calendar calendar)
      Sets the date based on a Calendar object. Modifies the Jewish date as well.
      Parameters:
      calendar - the Calendar to set the calendar to
      Throws:
      IllegalArgumentException - if the Calendar.ERA is GregorianCalendar.BC

    • setDate

      public void setDate(Date date)
      Sets the date based on a Date object. Modifies the Jewish date as well.
      Parameters:
      date - the Date to set the calendar to
      Throws:
      IllegalArgumentException - if the date would fall prior to the year 1 AD

    • setDate

      public void setDate(LocalDate localDate)
      Sets the date based on a LocalDate object. Modifies the Jewish date as well.
      Parameters:
      localDate - the LocalDate to set the calendar to
      Throws:
      IllegalArgumentException - if the date would fall prior to the year 1 AD

    • setGregorianDate

      public void setGregorianDate(int year, int month, int dayOfMonth)
      Sets the Gregorian Date, and updates the Jewish date accordingly. Like the Java Calendar A value of 0 is expected for January.
      Parameters:
      year - the Gregorian year
      month - the Gregorian month. Like the Java Calendar, this class expects 0 for January
      dayOfMonth - the Gregorian day of month. If this is > the number of days in the month/year, the last valid date of the month will be set
      Throws:
      IllegalArgumentException - if a year of < 1, a month < 0 or > 11 or a day of month < 1 is passed in

    • setInternalGregorianDate

      private void setInternalGregorianDate(int year, int month, int dayOfMonth)
      Sets the hidden internal representation of the Gregorian date , and updates the Jewish date accordingly. While public getters and setters have 0 based months matching the Java Calendar classes, This class internally represents the Gregorian month starting at 1. When this is called it will not adjust the month to match the Java Calendar classes.
      Parameters:
      year - the year
      month - the month
      dayOfMonth - the day of month

    • setJewishDate

      public void setJewishDate(int year, int month, int dayOfMonth)
      Sets the Jewish Date and updates the Gregorian date accordingly.
      Parameters:
      year - the Jewish year. The year can't be negative
      month - the Jewish month starting with Nisan. A value of 1 is expected for Nissan ... 12 for Adar and 13 for Adar II. Use the constants NISSAN ... ADAR (or ADAR_II for a leap year Adar II) to avoid any confusion.
      dayOfMonth - the Jewish day of month. valid values are 1-30. If the day of month is set to 30 for a month that only has 29 days, the day will be set as 29.
      Throws:
      IllegalArgumentException - if a A Jewish date earlier than 18 Teves, 3761 (1/1/1 Gregorian), a month < 1 or > 12 (or 13 on a leap year) or the day of month is < 1 or > 30 is passed in

    • setJewishDate

      public void setJewishDate(int year, int month, int dayOfMonth, int hours, int minutes, int chalakim)
      Sets the Jewish Date and updates the Gregorian date accordingly.
      Parameters:
      year - the Jewish year. The year can't be negative
      month - the Jewish month starting with Nisan. A value of 1 is expected for Nissan ... 12 for Adar and 13 for Adar II. Use the constants NISSAN ... ADAR (or ADAR_II for a leap year Adar II) to avoid any confusion.
      dayOfMonth - the Jewish day of month. valid values are 1-30. If the day of month is set to 30 for a month that only has 29 days, the day will be set as 29.
      hours - the hour of the day. Used for Molad calculations
      minutes - the minutes. Used for Molad calculations
      chalakim - the chalakim/parts. Used for Molad calculations. The chalakim should not exceed 17. Minutes should be used for larger numbers.
      Throws:
      IllegalArgumentException - if a A Jewish date earlier than 18 Teves, 3761 (1/1/1 Gregorian), a month < 1 or > 12 (or 13 on a leap year), the day of month is < 1 or > 30, an hour < 0 or > 23, a minute < 0 > 59 or chalakim < 0 > 17. For larger a larger number of chalakim such as 793 (TaShTzaG) break the chalakim into minutes (18 chalakim per minutes, so it would be 44 minutes and 1 chelek in the case of 793 (TaShTzaG).

    • getGregorianCalendar

      public Calendar getGregorianCalendar()
      Returns this object's date as a Calendar object.
      Returns:
      The Calendar

    • getLocalDate

      public LocalDate getLocalDate()
      Returns this object's date as a LocalDate object.
      Returns:
      The LocalDate

    • resetDate

      public void resetDate()
      Resets this date to the current system date.

    • toString

      public String toString()
      Returns a string containing the Jewish date in the form, "day Month, year" e.g. "21 Shevat, 5729". For more complex formatting, use the formatter classes.
      Overrides:
      toString in class Object
      Returns:
      the Jewish date in the form "day Month, year" e.g. "21 Shevat, 5729"
      See Also:

    • forward

      public void forward(int field, int amount)
      Rolls the date, month or year forward by the amount passed in. It modifies both the Gregorian and Jewish dates accordingly. If manipulation beyond the fields supported here is required, use the Calendar class Calendar.add(int, int) or Calendar.roll(int, int) methods in the following manner. 
       
        Calendar cal = jewishDate.getTime(); // get a java.util.Calendar representation of the JewishDate
        cal.add(Calendar.MONTH, 3); // add 3 Gregorian months
        jewishDate.setDate(cal); // set the updated calendar back to this class
      Parameters:
      field - the calendar field to be forwarded. The must be Calendar.DATE, Calendar.MONTH or Calendar.YEAR
      amount - the positive amount to move forward
      Throws:
      IllegalArgumentException - if the field is anything besides Calendar.DATE, Calendar.MONTH or Calendar.YEAR or if the amount is less than 1
      See Also:

    • forwardJewishMonth

      private void forwardJewishMonth(int amount)
      Forward the Jewish date by the number of months passed in. FIXME: Deal with forwarding a date such as 30 Nisan by a month. 30 Iyar does not exist. This should be dealt with similar to the way that the Java Calendar behaves (not that simple since there is a difference between add() or roll().
      Parameters:
      amount - the number of months to roll the month forward
      Throws:
      IllegalArgumentException - if the amount is less than 1

    • back

      public void back()
      Rolls the date back by 1 day. It modifies both the Gregorian and Jewish dates accordingly. The API does not currently offer the ability to forward more than one day at a time, or to forward by month or year. If such manipulation is required use the Calendar class Calendar.add(int, int) or Calendar.roll(int, int) methods in the following manner. 
       
        Calendar cal = jewishDate.getTime(); // get a java.util.Calendar representation of the JewishDate
        cal.add(Calendar.MONTH, -3); // subtract 3 Gregorian months
        jewishDate.setDate(cal); // set the updated calendar back to this class
      See Also:

    • equals

      public boolean equals(Object object)
      Indicates whether some other object is "equal to" this one.
      Overrides:
      equals in class Object
      See Also:

    • compareTo

      public int compareTo(JewishDate jewishDate)
      Compares two dates as per the compareTo() method in the Comparable interface. Returns a value less than 0 if this date is "less than" (before) the date, greater than 0 if this date is "greater than" (after) the date, or 0 if they are equal.
      Specified by:
      compareTo in interface Comparable<JewishDate>

    • getGregorianMonth

      public int getGregorianMonth()
      Returns the Gregorian month (between 0-11).
      Returns:
      the Gregorian month (between 0-11). Like the java.util.Calendar, months are 0 based.

    • getGregorianDayOfMonth

      public int getGregorianDayOfMonth()
      Returns the Gregorian day of the month.
      Returns:
      the Gregorian day of the mont

    • getGregorianYear

      public int getGregorianYear()
      Returns the Gregotian year.
      Returns:
      the Gregorian year

    • getJewishMonth

      public int getJewishMonth()
      Returns the Jewish month 1-12 (or 13 years in a leap year). The month count starts with 1 for Nisan and goes to 13 for Adar II
      Returns:
      the Jewish month from 1 to 12 (or 13 years in a leap year). The month count starts with 1 for Nisan and goes to 13 for Adar II

    • getJewishDayOfMonth

      public int getJewishDayOfMonth()
      Returns the Jewish day of month.
      Returns:
      the Jewish day of the month

    • getJewishYear

      public int getJewishYear()
      Returns the Jewish year.
      Returns:
      the Jewish year

    • getDayOfWeek

      public int getDayOfWeek()
      Returns the day of the week as a number between 1-7.
      Returns:
      the day of the week as a number between 1-7.

    • setGregorianMonth

      public void setGregorianMonth(int month)
      Sets the Gregorian month.
      Parameters:
      month - the Gregorian month
      Throws:
      IllegalArgumentException - if a month < 0 or > 11 is passed in

    • setGregorianYear

      public void setGregorianYear(int year)
      sets the Gregorian year.
      Parameters:
      year - the Gregorian year.
      Throws:
      IllegalArgumentException - if a year of < 1 is passed in

    • setGregorianDayOfMonth

      public void setGregorianDayOfMonth(int dayOfMonth)
      sets the Gregorian Day of month.
      Parameters:
      dayOfMonth - the Gregorian Day of month.
      Throws:
      IllegalArgumentException - if the day of month of < 1 is passed in

    • setJewishMonth

      public void setJewishMonth(int month)
      sets the Jewish month.
      Parameters:
      month - the Jewish month from 1 to 12 (or 13 years in a leap year). The month count starts with 1 for Nisan and goes to 13 for Adar II
      Throws:
      IllegalArgumentException - if a month < 1 or > 12 (or 13 on a leap year) is passed in

    • setJewishYear

      public void setJewishYear(int year)
      sets the Jewish year.
      Parameters:
      year - the Jewish year
      Throws:
      IllegalArgumentException - if a year of < 3761 is passed in. The same will happen if the year is 3761 and the month and day previously set are < 18 Teves (preior to Jan 1, 1 AD)

    • setJewishDayOfMonth

      public void setJewishDayOfMonth(int dayOfMonth)
      sets the Jewish day of month.
      Parameters:
      dayOfMonth - the Jewish day of month
      Throws:
      IllegalArgumentException - if the day of month is < 1 or > 30 is passed in

    • clone

      public Object clone()
      A method that creates a deep copy of the object.
      Overrides:
      clone in class Object
      See Also:

    • hashCode

      public int hashCode()
      Overrides Object.hashCode().
      Overrides:
      hashCode in class Object
      See Also: