Package org.shredzone.commons.suncalc.util

Class JulianDate

java.lang.Object

org.shredzone.commons.suncalc.util.JulianDate

public class JulianDate
extends Object

This class contains a Julian Date representation of a date.

Objects are immutable and threadsafe.

Constructor Summary

Constructors

Constructor	Description
JulianDate(Calendar cal)	Creates a new JulianDate.

Method Summary

Modifier and Type	Method	Description
JulianDate	atHour(double hour)	Returns a JulianDate of the current date and the given hour.
JulianDate	atJulianCentury(double jc)	Returns a JulianDate of the given Julian century.
JulianDate	atModifiedJulianDate(double mjd)	Returns a JulianDate of the given modified Julian date.
Calendar	getCalendar()	Returns this JulianDate as Calendar object.
Date	getDate()	Returns this JulianDate as Date object.
Date	getDateTruncated(TimeResultParameter.Unit unit)	Returns this JulianDate as truncated Date object.
double	getGreenwichMeanSiderealTime()	Returns the Greenwich Mean Sidereal Time of this Julian Date.
double	getJulianCentury()	Returns the Julian Centuries.
double	getModifiedJulianDate()	Returns the Modified Julian Date.
double	getTrueAnomaly()	Returns the earth's true anomaly of the current date.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

JulianDate

public JulianDate(Calendar cal)

Creates a new JulianDate.

Parameters:

cal - Calendar to use. Do not modify this object after invocation.

Method Details

atHour

public JulianDate atHour(double hour)

Returns a JulianDate of the current date and the given hour.

Parameters:

hour - Hour of this date. This is a floating point value. Fractions are used for minutes and seconds.

Returns:

JulianDate instance.

atModifiedJulianDate

public JulianDate atModifiedJulianDate(double mjd)

Returns a JulianDate of the given modified Julian date.

Parameters:

mjd - Modified Julian Date

Returns:

JulianDate instance.

Since:

2.3

atJulianCentury

public JulianDate atJulianCentury(double jc)

Returns a JulianDate of the given Julian century.

Parameters:

jc - Julian Century

Returns:

JulianDate instance.

Since:

2.3

getDate

public Date getDate()

Returns this JulianDate as Date object.

Returns:

Date of this JulianDate.

getDateTruncated

public Date getDateTruncated(TimeResultParameter.Unit unit)

Returns this JulianDate as truncated Date object.

Parameters:

unit - TimeResultParameter.Unit to truncate to

Returns:

Rounded Date of this JulianDate.

Since:

2.3

getCalendar

public Calendar getCalendar()

Returns this JulianDate as Calendar object.

Returns:

New Calendar instance of this JulianDate.

getModifiedJulianDate

public double getModifiedJulianDate()

Returns the Modified Julian Date.

Returns:

Modified Julian Date, UTC.

getJulianCentury

public double getJulianCentury()

Returns the Julian Centuries.

Returns:

Julian Centuries, based on J2000 epoch, UTC.

getGreenwichMeanSiderealTime

public double getGreenwichMeanSiderealTime()

Returns the Greenwich Mean Sidereal Time of this Julian Date.

Returns:

GMST

getTrueAnomaly

public double getTrueAnomaly()

Returns the earth's true anomaly of the current date.

A simple approximation is used here.

Returns:

True anomaly, in radians

toString

public String toString()

Overrides:

toString in class Object