Package org.joda.time.chrono

Class GregorianChronology

java.lang.Object

org.joda.time.Chronology

org.joda.time.chrono.BaseChronology

org.joda.time.chrono.AssembledChronology

org.joda.time.chrono.BasicChronology

org.joda.time.chrono.BasicGJChronology

org.joda.time.chrono.GregorianChronology

All Implemented Interfaces:

Serializable

public final class GregorianChronology
extends BasicGJChronology

Implements a pure proleptic Gregorian calendar system, which defines every fourth year as leap, unless the year is divisible by 100 and not by 400. This improves upon the Julian calendar leap year rule.

Although the Gregorian calendar did not exist before 1582 CE, this chronology assumes it did, thus it is proleptic. This implementation also fixes the start of the year at January 1, and defines the year zero.

GregorianChronology is thread-safe and immutable.

Since:

1.0

See Also:

• Wikipedia
• JulianChronology
• GJChronology
• Serialized Form

Nested Class Summary

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

AssembledChronology.Fields

Field Summary

Fields

Modifier and Type	Field	Description
private static final ConcurrentHashMap<DateTimeZone,GregorianChronology[]>	cCache	Cache of zone to chronology arrays
private static final int	DAYS_0000_TO_1970
private static final GregorianChronology	INSTANCE_UTC	Singleton instance of a UTC GregorianChronology
private static final int	MAX_YEAR	The highest year that can be fully supported.
private static final long	MILLIS_PER_MONTH
private static final long	MILLIS_PER_YEAR
private static final int	MIN_YEAR	The lowest year that can be fully supported.
private static final long	serialVersionUID	Serialization lock

Constructor Summary

Constructors

Modifier	Constructor	Description
private	GregorianChronology(Chronology base, Object param, int minDaysInFirstWeek)	Restricted constructor

Method Summary

Modifier and Type	Method	Description
protected void	assemble(AssembledChronology.Fields fields)	Invoked by the constructor and after deserialization to allow subclasses to define all of its supported fields.
(package private) long	calculateFirstDayOfYearMillis(int year)	Gets the millisecond value of the first day of the year.
(package private) long	getApproxMillisAtEpochDividedByTwo()	Returns a constant representing the approximate number of milliseconds elapsed from year 0 of this chronology, divided by two.
(package private) long	getAverageMillisPerMonth()	Gets an average value for the milliseconds per month.
(package private) long	getAverageMillisPerYear()	Gets an average value for the milliseconds per year.
(package private) long	getAverageMillisPerYearDividedByTwo()	Gets an average value for the milliseconds per year, divided by two.
static GregorianChronology	getInstance()	Gets an instance of the GregorianChronology in the default time zone.
static GregorianChronology	getInstance(DateTimeZone zone)	Gets an instance of the GregorianChronology in the given time zone.
static GregorianChronology	getInstance(DateTimeZone zone, int minDaysInFirstWeek)	Gets an instance of the GregorianChronology in the given time zone.
static GregorianChronology	getInstanceUTC()	Gets an instance of the GregorianChronology.
(package private) int	getMaxYear()	Gets the maximum supported year.
(package private) int	getMinYear()	Gets the minimum supported year.
(package private) boolean	isLeapYear(int year)	Is the specified year a leap year?
private Object	readResolve()	Serialization singleton
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.BasicGJChronology

getDaysInMonthMax, getDaysInMonthMaxForSet, getDaysInYearMonth, getMonthOfYear, getTotalMillisByYearMonth, getYearDifference, isLeapDay, setYear

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

equals, getDateMidnightMillis, getDateTimeMillis, getDateTimeMillis, getDayOfMonth, getDayOfMonth, getDayOfMonth, getDayOfWeek, getDayOfYear, getDayOfYear, getDaysInMonthMax, getDaysInMonthMax, getDaysInYear, getDaysInYearMax, getFirstWeekOfYearMillis, getMaxMonth, getMaxMonth, getMillisOfDay, getMinimumDaysInFirstWeek, getMonthOfYear, getWeekOfWeekyear, getWeekOfWeekyear, getWeeksInYear, getWeekyear, getYear, getYearMillis, getYearMonthDayMillis, getYearMonthMillis, getZone, hashCode, toString

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

centuries, centuryOfEra, clockhourOfDay, clockhourOfHalfday, dayOfMonth, dayOfWeek, dayOfYear, days, era, eras, getBase, getDateTimeMillis, getParam, 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 java.lang.Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

Serialization lock

See Also:

• Constant Field Values

MILLIS_PER_YEAR

private static final long MILLIS_PER_YEAR

See Also:

• Constant Field Values

MILLIS_PER_MONTH

private static final long MILLIS_PER_MONTH

See Also:

• Constant Field Values

DAYS_0000_TO_1970

private static final int DAYS_0000_TO_1970

See Also:

• Constant Field Values

MIN_YEAR

private static final int MIN_YEAR

The lowest year that can be fully supported.

See Also:

• Constant Field Values

MAX_YEAR

private static final int MAX_YEAR

The highest year that can be fully supported.

See Also:

• Constant Field Values

INSTANCE_UTC

private static final GregorianChronology INSTANCE_UTC

Singleton instance of a UTC GregorianChronology

cCache

private static final ConcurrentHashMap<DateTimeZone,GregorianChronology[]> cCache

Cache of zone to chronology arrays

Constructor Details

GregorianChronology

private GregorianChronology(Chronology base,
 Object param,
 int minDaysInFirstWeek)

Restricted constructor

Method Details

getInstanceUTC

public static GregorianChronology getInstanceUTC()

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

Returns:

a singleton UTC instance of the chronology

getInstance

public static GregorianChronology getInstance()

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

Returns:

a chronology in the default time zone

getInstance

public static GregorianChronology getInstance(DateTimeZone zone)

Gets an instance of the GregorianChronology 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

getInstance

public static GregorianChronology getInstance(DateTimeZone zone,
 int minDaysInFirstWeek)

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

Parameters:

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

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

Returns:

a chronology in the specified time zone

readResolve

private Object readResolve()

Serialization singleton

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

assemble

protected void assemble(AssembledChronology.Fields fields)

Description copied from class: AssembledChronology

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

Overrides:

assemble in class BasicChronology

Parameters:

fields - container of fields

isLeapYear

boolean isLeapYear(int year)

Description copied from class: BasicChronology

Is the specified year a leap year?

Specified by:

isLeapYear in class BasicChronology

Parameters:

year - the year to test

Returns:

true if leap

calculateFirstDayOfYearMillis

long calculateFirstDayOfYearMillis(int year)

Description copied from class: BasicChronology

Gets the millisecond value of the first day of the year.

Specified by:

calculateFirstDayOfYearMillis in class BasicChronology

Returns:

the milliseconds for the first of the year

getMinYear

int getMinYear()

Description copied from class: BasicChronology

Gets the minimum supported year.

Specified by:

getMinYear in class BasicChronology

Returns:

the year

getMaxYear

int getMaxYear()

Description copied from class: BasicChronology

Gets the maximum supported year.

Specified by:

getMaxYear in class BasicChronology

Returns:

the year

getAverageMillisPerYear

long getAverageMillisPerYear()

Description copied from class: BasicChronology

Gets an average value for the milliseconds per year.

Specified by:

getAverageMillisPerYear in class BasicChronology

Returns:

the millis per year

getAverageMillisPerYearDividedByTwo

long getAverageMillisPerYearDividedByTwo()

Description copied from class: BasicChronology

Gets an average value for the milliseconds per year, divided by two.

Specified by:

getAverageMillisPerYearDividedByTwo in class BasicChronology

Returns:

the millis per year divided by two

getAverageMillisPerMonth

long getAverageMillisPerMonth()

Description copied from class: BasicChronology

Gets an average value for the milliseconds per month.

Specified by:

getAverageMillisPerMonth in class BasicChronology

Returns:

the millis per month

getApproxMillisAtEpochDividedByTwo

long getApproxMillisAtEpochDividedByTwo()

Description copied from class: BasicChronology

Returns a constant representing the approximate number of milliseconds elapsed from year 0 of this chronology, divided by two. This constant must be defined as:

    (yearAtEpoch * averageMillisPerYear + millisOfYearAtEpoch) / 2
 

where epoch is 1970-01-01 (Gregorian).

Specified by:

getApproxMillisAtEpochDividedByTwo in class BasicChronology