public final class

IslamicChronology

extends AssembledChronology
java.lang.Object
   ↳ org.joda.time.Chronology
     ↳ org.joda.time.chrono.BaseChronology
       ↳ org.joda.time.chrono.AssembledChronology
         ↳ org.joda.time.chrono.IslamicChronology

Class Overview

Implements the Islamic, or Hijri, calendar system using arithmetic rules.

This calendar is a lunar calendar with a shorter year than ISO. Year 1 in the Islamic calendar began on July 16, 622 CE (Julian), thus Islamic years do not begin at the same time as Julian years. This chronology is not proleptic, as it does not allow dates before the first Islamic year.

There are two basic forms of the Islamic calendar, the tabular and the observed. The observed form cannot easily be used by computers as it relies on human observation of the new moon. The tabular calendar, implemented here, is an arithmetical approximation of the observed form that follows relatively simple rules.

The tabular form of the calendar defines 12 months of alternately 30 and 29 days. The last month is extended to 30 days in a leap year. Leap years occur according to a 30 year cycle. There are four recognised patterns of leap years in the 30 year cycle: 

 Years 2, 5, 7, 10, 13, 15, 18, 21, 24, 26 & 29 - 15-based, used by Microsoft
 Years 2, 5, 7, 10, 13, 16, 18, 21, 24, 26 & 29 - 16-based, most commonly used
 Years 2, 5, 8, 10, 13, 16, 19, 21, 24, 27 & 29 - Indian
 Years 2, 5, 8, 11, 13, 16, 19, 21, 24, 27 & 30 - Habash al-Hasib
You can select which pattern to use via the factory methods, or use the default (16-based).

This implementation defines a day as midnight to midnight exactly as per the ISO chronology. This correct start of day is at sunset on the previous day, however this cannot readily be modelled and has been ignored.

IslamicChronology is thread-safe and immutable.

See Also

Summary

Nested Classes
class IslamicChronology.LeapYearPatternType Opaque object describing a leap year pattern for the Islamic Chronology. 
Constants
int AH Constant value for 'Anno Hegirae', equivalent to the value returned for AD/CE.
Fields
public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_15_BASED Leap year 15-based pattern.
public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_16_BASED Leap year 16-based pattern.
public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_HABASH_AL_HASIB Leap year Habash al-Hasib pattern.
public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_INDIAN Leap year Indian pattern.
Public Methods
boolean equals(Object obj)
Checks if this chronology instance equals another.
long getDateTimeMillis(int year, int monthOfYear, int dayOfMonth, int millisOfDay)
Returns a datetime millisecond instant, formed from the given year, month, day, and millisecond values.
long getDateTimeMillis(int year, int monthOfYear, int dayOfMonth, int hourOfDay, int minuteOfHour, int secondOfMinute, int millisOfSecond)
Returns a datetime millisecond instant, formed from the given year, month, day, hour, minute, second, and millisecond values.
static IslamicChronology getInstance()
Gets an instance of the IslamicChronology in the default time zone.
static IslamicChronology getInstance(DateTimeZone zone, IslamicChronology.LeapYearPatternType leapYears)
Gets an instance of the IslamicChronology in the given time zone.
static IslamicChronology getInstance(DateTimeZone zone)
Gets an instance of the IslamicChronology in the given time zone.
static IslamicChronology getInstanceUTC()
Gets an instance of the IslamicChronology.
IslamicChronology.LeapYearPatternType getLeapYearPatternType()
Gets the leap year pattern type.
int getMinimumDaysInFirstWeek()
DateTimeZone getZone()
Returns the DateTimeZone that this Chronology operates in, or null if unspecified.
int hashCode()
A suitable hash code for the chronology.
String toString()
Gets a debugging toString.
Chronology withUTC()
Gets the Chronology in the UTC time zone.
Chronology withZone(DateTimeZone zone)
Gets the Chronology in a specific time zone.
Protected Methods
void assemble(AssembledChronology.Fields fields)
Invoked by the constructor and after deserialization to allow subclasses to define all of its supported fields.
[Expand]
Inherited Methods
From class org.joda.time.chrono.AssembledChronology
From class org.joda.time.chrono.BaseChronology
From class org.joda.time.Chronology
From class java.lang.Object

Constants

public static final int AH

Constant value for 'Anno Hegirae', equivalent to the value returned for AD/CE.

Constant Value: 1 (0x00000001)

Fields

public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_15_BASED

Leap year 15-based pattern.

public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_16_BASED

Leap year 16-based pattern.

public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_HABASH_AL_HASIB

Leap year Habash al-Hasib pattern.

public static final IslamicChronology.LeapYearPatternType LEAP_YEAR_INDIAN

Leap year Indian pattern.

Public Methods

public boolean equals (Object obj)

Checks if this chronology instance equals another.

Parameters
obj the object to compare to
Returns
  • true if equal

public long getDateTimeMillis (int year, int monthOfYear, int dayOfMonth, int millisOfDay)

Returns a datetime millisecond instant, formed from the given year, month, day, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

Parameters
year year to use
monthOfYear month to use
dayOfMonth day of month to use
millisOfDay millisecond to use
Returns
  • millisecond instant from 1970-01-01T00:00:00Z
Throws
IllegalArgumentException

public long getDateTimeMillis (int year, int monthOfYear, int dayOfMonth, int hourOfDay, int minuteOfHour, int secondOfMinute, int millisOfSecond)

Returns a datetime millisecond instant, formed from the given year, month, day, hour, minute, second, and millisecond values. The set of given values must refer to a valid datetime, or else an IllegalArgumentException is thrown.

The default implementation calls upon separate DateTimeFields to determine the result. Subclasses are encouraged to provide a more efficient implementation.

Parameters
year year to use
monthOfYear month to use
dayOfMonth day of month to use
hourOfDay hour to use
minuteOfHour minute to use
secondOfMinute second to use
millisOfSecond millisecond to use
Returns
  • millisecond instant from 1970-01-01T00:00:00Z
Throws
IllegalArgumentException

public static IslamicChronology getInstance ()

Gets an instance of the IslamicChronology in the default time zone.

Returns
  • a chronology in the default time zone

public static IslamicChronology getInstance (DateTimeZone zone, IslamicChronology.LeapYearPatternType leapYears)

Gets an instance of the IslamicChronology in the given time zone.

Parameters
zone the time zone to get the chronology in, null is default
leapYears the type defining the leap year pattern
Returns
  • a chronology in the specified time zone

public static IslamicChronology getInstance (DateTimeZone zone)

Gets an instance of the IslamicChronology in the given time zone.

Parameters
zone the time zone to get the chronology in, null is default
Returns
  • a chronology in the specified time zone

public static IslamicChronology getInstanceUTC ()

Gets an instance of the IslamicChronology. The time zone of the returned instance is UTC.

Returns
  • a singleton UTC instance of the chronology

public IslamicChronology.LeapYearPatternType getLeapYearPatternType ()

Gets the leap year pattern type.

Returns
  • the pattern type

public int getMinimumDaysInFirstWeek ()

public DateTimeZone getZone ()

Returns the DateTimeZone that this Chronology operates in, or null if unspecified.

Returns
  • DateTimeZone null if unspecified

public int hashCode ()

A suitable hash code for the chronology.

Returns
  • the hash code

public String toString ()

Gets a debugging toString.

Returns
  • a debugging string

public Chronology withUTC ()

Gets the Chronology in the UTC time zone.

Returns
  • the chronology in UTC

public Chronology withZone (DateTimeZone zone)

Gets the Chronology in a specific time zone.

Parameters
zone the zone to get the chronology in, null is default
Returns
  • the chronology

Protected Methods

protected void assemble (AssembledChronology.Fields fields)

Invoked by the constructor and after deserialization to allow subclasses to define all of its supported fields. All unset fields default to unsupported instances.

Parameters
fields container of fields