net.time4j.calendar.astro

Enum AstronomicalSeason

java.lang.Object

java.lang.Enum<AstronomicalSeason>

net.time4j.calendar.astro.AstronomicalSeason

All Implemented Interfaces:

Serializable, Comparable<AstronomicalSeason>

public enum AstronomicalSeason
extends Enum<AstronomicalSeason>

The four astronomical seasons (Spring, Summer, Autumn and Winter).

If there is no context information then Time4J will assume that any season is related to the northern hemisphere.

Since:

3.33/4.28

Author:

Meno Hochschild

Enum Constant Summary

Enum Constants

Enum Constant and Description
AUTUMNAL_EQUINOX Begin of Autumn on the northern hemisphere in September (or Spring on the southern hemisphere).
SUMMER_SOLSTICE Begin of Summer on the northern hemisphere in June (or Winter on the southern hemisphere).
VERNAL_EQUINOX Begin of Spring on the northern hemisphere in March (or Autumn on the southern hemisphere).
WINTER_SOLSTICE Begin of Winter on the northern hemisphere in December (or Summer on the southern hemisphere).

Method Summary

Modifier and Type	Method and Description
Moment	inYear(int year) Determines the moment of this astronomical event in given year.
JulianDay	julianDay(int year) Determines the Julian day of this astronomical event in given year.
static AstronomicalSeason	of(Moment moment) Determines the astronomical season related to given moment.
AstronomicalSeason	onNorthernHemisphere() Interpretes this season as related to the northern hemisphere and returns this instance unchanged.
AstronomicalSeason	onSouthernHemisphere() Interpretes this season as related to the southern hemisphere and returns the corresponding northern equivalent.
static AstronomicalSeason	valueOf(String name) Returns the enum constant of this type with the specified name.
static AstronomicalSeason[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

compareTo, equals, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

VERNAL_EQUINOX

public static final AstronomicalSeason VERNAL_EQUINOX

Begin of Spring on the northern hemisphere in March (or Autumn on the southern hemisphere).

SUMMER_SOLSTICE

public static final AstronomicalSeason SUMMER_SOLSTICE

Begin of Summer on the northern hemisphere in June (or Winter on the southern hemisphere).

AUTUMNAL_EQUINOX

public static final AstronomicalSeason AUTUMNAL_EQUINOX

Begin of Autumn on the northern hemisphere in September (or Spring on the southern hemisphere).

WINTER_SOLSTICE

public static final AstronomicalSeason WINTER_SOLSTICE

Begin of Winter on the northern hemisphere in December (or Summer on the southern hemisphere).

Method Detail

values

public static AstronomicalSeason[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (AstronomicalSeason c : AstronomicalSeason.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static AstronomicalSeason valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

of

public static AstronomicalSeason of(Moment moment)

Determines the astronomical season related to given moment.

The result will be valid for the northern hemisphere. For the southern equivalent, please call the method onSouthernHemisphere() on the result.

Parameters:

moment - the moment/instant for which the season is to be determined

Returns:

astronomical season (on the northern hemisphere)

Throws:

IllegalArgumentException - if the year is out of range -2000 <= year <= +3000

Since:

5.2

inYear

public Moment inYear(int year)

Determines the moment of this astronomical event in given year.

The precision is for modern times (around 2000) better than a minute. The underlying astronomical calculations are based on formula given by Jean Meeus in his book "Astronomical algorithms".

Parameters:

year - gregorian/julian year

Returns:

time of this astronomical event (equinox or solstice) in given year

Throws:

IllegalArgumentException - if the year is out of range -2000 <= year <= +3000

julianDay

public JulianDay julianDay(int year)

Determines the Julian day of this astronomical event in given year.

The precision is for modern times (around 2000) better than a minute. The underlying astronomical calculations are based on formula given by Jean Meeus in his book "Astronomical algorithms".

Parameters:

year - gregorian/julian year

Returns:

JD(TT) of this astronomical event (equinox or solstice) in given year

Throws:

IllegalArgumentException - if the year is out of range -2000 <= year <= +3000

See Also:

JulianDay.ofEphemerisTime(double)

onNorthernHemisphere

public AstronomicalSeason onNorthernHemisphere()

Interpretes this season as related to the northern hemisphere and returns this instance unchanged.

This method does not change anything but serves for better documentation and more clarity about the meaning of this season.

Returns:

this instance (identity operation)

Since:

3.35/4.30

See Also:

onSouthernHemisphere()

onSouthernHemisphere

public AstronomicalSeason onSouthernHemisphere()

Interpretes this season as related to the southern hemisphere and returns the corresponding northern equivalent.

Returns:

northern equivalent of this season

Since:

3.35/4.30

See Also:

onNorthernHemisphere()