org.joda.time.chrono
Class GJChronology

java.lang.Object
  org.joda.time.Chronology
      org.joda.time.chrono.BaseChronology
          org.joda.time.chrono.AssembledChronology
              org.joda.time.chrono.GJChronology

All Implemented Interfaces:

Serializable

public final class GJChronology

extends AssembledChronology

Implements the Gregorian/Julian calendar system which is the calendar system used in most of the world. Wherever possible, it is recommended to use the ISOChronology instead.

The Gregorian calendar replaced the Julian calendar, and the point in time when this chronology switches can be controlled using the second parameter of the getInstance method. By default this cutover is set to the date the Gregorian calendar was first instituted, October 15, 1582.

Before this date, this chronology uses the proleptic Julian calendar (proleptic means extending indefinitely). The Julian calendar has leap years every four years, whereas the Gregorian has special rules for 100 and 400 years. A meaningful result will thus be obtained for all input values. However before 8 CE, Julian leap years were irregular, and before 45 BCE there was no Julian calendar.

This chronology differs from GregorianCalendar in that years in BCE are returned correctly. Thus year 1 BCE is returned as -1 instead of 1. The yearOfEra field produces results compatible with GregorianCalendar.

The Julian calendar does not have a year zero, and so year -1 is followed by year 1. If the Gregorian cutover date is specified at or before year -1 (Julian), year zero is defined. In other words, the proleptic Gregorian chronology used by this class has a year zero.

To create a pure proleptic Julian chronology, use JulianChronology, and to create a pure proleptic Gregorian chronology, use GregorianChronology.

GJChronology is thread-safe and immutable.

Since:

1.0

Author:

Brian S O'Neill, Stephen Colebourne

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class org.joda.time.chrono.AssembledChronology

AssembledChronology.Fields

Method Summary

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.
Instant	getGregorianCutover() Gets the cutover instant between Gregorian and Julian chronologies.
static GJChronology	getInstance() Factory method returns instances of the default GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone) Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, long gregorianCutover, int minDaysInFirstWeek) Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, ReadableInstant gregorianCutover) Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstance(DateTimeZone zone, ReadableInstant gregorianCutover, int minDaysInFirstWeek) Factory method returns instances of the GJ cutover chronology.
static GJChronology	getInstanceUTC() Factory method returns instances of the default GJ cutover chronology.
int	getMinimumDaysInFirstWeek() Gets the minimum days needed for a week to be the first week in a year.
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.

Methods inherited from class org.joda.time.chrono.AssembledChronology

centuries, centuryOfEra, clockhourOfDay, clockhourOfHalfday, dayOfMonth, dayOfWeek, dayOfYear, days, era, eras, getDateTimeMillis, halfdayOfDay, halfdays, hourOfDay, hourOfHalfday, hours, millis, millisOfDay, millisOfSecond, minuteOfDay, minuteOfHour, minutes, monthOfYear, months, secondOfDay, secondOfMinute, seconds, weekOfWeekyear, weeks, weekyear, weekyearOfCentury, weekyears, year, yearOfCentury, yearOfEra, years

Methods inherited from class org.joda.time.chrono.BaseChronology

add, add, get, get, get, set, validate

Methods inherited from class org.joda.time.Chronology

getBuddhist, getBuddhist, getBuddhistUTC, getCoptic, getCoptic, getCopticUTC, getGJ, getGJ, getGJUTC, getGregorian, getGregorian, getGregorianUTC, getISO, getISO, getISOUTC, getJulian, getJulian, getJulianUTC

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Method Detail

getInstanceUTC

public static GJChronology getInstanceUTC()

Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

The time zone of the returned instance is UTC.

getInstance

public static GJChronology getInstance()

Factory method returns instances of the default GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

The returned chronology is in the default time zone.

getInstance

public static GJChronology getInstance(DateTimeZone zone)

Factory method returns instances of the GJ cutover chronology. This uses a cutover date of October 15, 1582 (Gregorian) 00:00:00 UTC. For this value, October 4, 1582 (Julian) is followed by October 15, 1582 (Gregorian).

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

Parameters:

zone - the time zone to use, null is default

getInstance

public static GJChronology getInstance(DateTimeZone zone,
                                       ReadableInstant gregorianCutover)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

The first day of the week is designated to be Monday, and the minimum days in the first week of the year is 4.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use, null means default

getInstance

public static GJChronology getInstance(DateTimeZone zone,
                                       ReadableInstant gregorianCutover,
                                       int minDaysInFirstWeek)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use, null means default

minDaysInFirstWeek - minimum number of days in first week of the year; default is 4

getInstance

public static GJChronology getInstance(DateTimeZone zone,
                                       long gregorianCutover,
                                       int minDaysInFirstWeek)

Factory method returns instances of the GJ cutover chronology. Any cutover date may be specified.

Parameters:

zone - the time zone to use, null is default

gregorianCutover - the cutover to use

minDaysInFirstWeek - minimum number of days in first week of the year; default is 4

getZone

public DateTimeZone getZone()

Description copied from class: BaseChronology

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

Overrides:

getZone in class AssembledChronology

withUTC

public Chronology withUTC()

Gets the Chronology in the UTC time zone.

Specified by:

withUTC in class BaseChronology

Returns:

the chronology in UTC

withZone

public Chronology withZone(DateTimeZone zone)

Gets the Chronology in a specific time zone.

Specified by:

withZone in class BaseChronology

Parameters:

zone - the zone to get the chronology in, null is default

Returns:

the chronology

See Also:

ZonedChronology

getDateTimeMillis

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

Description copied from class: BaseChronology

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.

Overrides:

getDateTimeMillis in class AssembledChronology

Throws:

IllegalArgumentException

getDateTimeMillis

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

Description copied from class: BaseChronology

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.

Overrides:

getDateTimeMillis in class AssembledChronology

Throws:

IllegalArgumentException

getGregorianCutover

public Instant getGregorianCutover()

Gets the cutover instant between Gregorian and Julian chronologies.

Returns:

the cutover instant

getMinimumDaysInFirstWeek

public int getMinimumDaysInFirstWeek()

Gets the minimum days needed for a week to be the first week in a year.

Returns:

the minimum days

equals

public boolean equals(Object obj)

Checks if this chronology instance equals another.

Parameters:

obj - the object to compare to

Returns:

true if equal

Since:

1.6

hashCode

public int hashCode()

A suitable hash code for the chronology.

Returns:

the hash code

Since:

1.6

toString

public String toString()

Gets a debugging toString.

Specified by:

toString in class BaseChronology

Returns:

a debugging string