com.raben.util
Class JulianDay

java.lang.Object
  |
  +--com.raben.util.JulianDay

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

public final class JulianDay

extends java.lang.Object

implements java.io.Serializable, java.lang.Cloneable

Routines for calculating and setting Julian day number based on algorithms from Jean Meeus, "Astronomical Algorithms", 2nd Edition, Willmann-Bell, Inc., 1998.

Version:

$Revision: 1.19 $ $Date: 2002/12/12 20:46:29 $

Author:

Vern Raben (mailto:vern@raben.com)

See Also:

Serialized Form

Field Summary

static int	APRIL
static int	AUGUST
static int	DATE
static int	DAY_OF_MONTH
static int	DAY_OF_WEEK
static int	DAY_OF_YEAR
static int	DECEMBER
static double	EPOCH_0
static double	EPOCH_1970
static int	FEBRUARY
static int	HOUR
static int	HOUR_OF_DAY
static int	JANUARY
static int	JD
static int	JULY
static int	JUNE
static int	MARCH
static int	MAY
static int	MINUTE
static int	MJD
static int	MONTH
static java.lang.String[]	MONTHS
static int	NOVEMBER
static int	OCTOBER
static int	SECOND
static int	SEPTEMBER
static java.lang.String	SQL_DATE_FORMAT
static java.lang.String[]	TIME_UNIT
static int	YEAR

Constructor Summary

JulianDay()
JulianCalendar constructor - sets JD for current time

JulianDay(java.util.Calendar cal)
Construct JulianDate given Calendar as a parameter

JulianDay(double jd)
JulianCalendar constructor - sets JD passed as double

JulianDay(int yr, int mo, double da)
Constructor to create Julian day given year, month, and decimal day

JulianDay(int yr, int mo, int da)
Construct JulianDate given year, month, and date

JulianDay(int yr, int mo, int da, int hr, int min)
Construct JulianDate given year, month, date, hour and minute

JulianDay(int yr, int mo, int da, int hr, int min, int sec)
Construct JulianDate given year, month, day, hour, minute, and second

JulianDay(JulianDay cal)
Copy constructor for JulianDate

JulianDay(long timeInMilliSec)
Construct JulianDay from system time in milli-seconds since Jan 1, 1970

JulianDay(java.lang.String str)
Set JulianDay from sql database compatible date/time string (yyyy-mm-dd hh:mm:ss)

Method Summary

void	add(int unit, double val) Add specified value in specified time unit to current Julian Date increments next higher field ISSUE - meaning of incrementing YEAR and MONTH by fractional value is not clear since period of a month and year varies, that is ignored.
void	add(int unit, int val) Add specified value in specified time unit to current Julian Date increments next higher field ISSUE - meaning of incrementing YEAR and MONTH by fractional value is not clear since period of a month and year varies, that is ignored.
java.lang.Object	clone() Return clone of JulianDay object
double	diff(JulianDay date) Returns time difference in days between date specified and the JulianDay of this object (parameter date-this date)
boolean	equals(double jd) Returns true if Julian day number is within 0.001 of parameter jd
boolean	equals(JulianDay date) Return true if JulianDates are equal, false otherwise
int	get(int field) Returns the specified field
java.util.Calendar	getCalendar() Get java Calendar equivalent of Julian Day
java.lang.String	getDateTimeStr()
static double	getIncrement(int unit, int incr) Get increment in days given time unit and increment
double	getJDN() Returns the Julian Date Number as a double
long	getMilliSeconds() Returns milli-seconds since Jan 1, 1970
double	getMJD() Return the modified Julian date
java.util.Date	getTime() Return Java Date
java.lang.String	getYMD(int leastUnit) Return date as YYYYMMDDHHSS string with the least unit to be returned specified For example to to return YYYYMMDD specify least unit as JulianDay.DATE
void	set(int field, double value) This method sets Julian day or modified Julian day
void	set(int field, int value) Set various JulianCalendar fields Example: JulianDay jd=new JulianDay(); jd.set(Calendar.YEAR,1999);
void	set(int year, int month, int date) Set year, month, and day
void	set(int year, int month, int date, int hour, int minute) Set year, month,day, hour and minute
void	set(int year, int month, int date, int hour, int minute, int second) Set year month, day, hour, minute and second
void	set(JulianDay jd)
void	setDateFormat(java.text.SimpleDateFormat dateFormat) Set SimpleDateFormat for displaying date/time string
void	setDateFormat(java.lang.String formatStr) Set SimpleDateFormat string ISSUE - only valid after Jan 1, 1970
void	setDateTime(java.lang.String str) Set date/time from string
void	setEndOfDay() set hour to 23, minute and second to 59
void	setStartOfDay() Set hour,minute, and second to 0
void	setTime(java.util.Date dat) Set date from Java Date
void	setYMD(java.lang.String str) Set date from sting in the form YYYYMMDDhhmmss (YYYY=year MM=month DD=day hh=hr mm=min ss=sec)
java.lang.String	toString()
void	update() Update JulianDay to current time

Methods inherited from class java.lang.Object

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

Field Detail

JD

public static final int JD

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Constant Field Values

MJD

public static final int MJD

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Constant Field Values

YEAR

public static final int YEAR

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Constant Field Values

MONTH

public static final int MONTH

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Constant Field Values

DATE

public static final int DATE

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Constant Field Values

HOUR

public static final int HOUR

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Constant Field Values

HOUR_OF_DAY

public static final int HOUR_OF_DAY

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Constant Field Values

MINUTE

public static final int MINUTE

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Constant Field Values

SECOND

public static final int SECOND

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Constant Field Values

DAY_OF_YEAR

public static final int DAY_OF_YEAR

See Also:

Constant Field Values

DAY_OF_WEEK

public static final int DAY_OF_WEEK

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Constant Field Values

DAY_OF_MONTH

public static final int DAY_OF_MONTH

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Constant Field Values

JANUARY

public static final int JANUARY

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Constant Field Values

FEBRUARY

public static final int FEBRUARY

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Constant Field Values

MARCH

public static final int MARCH

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Constant Field Values

APRIL

public static final int APRIL

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Constant Field Values

MAY

public static final int MAY

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Constant Field Values

JUNE

public static final int JUNE

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Constant Field Values

JULY

public static final int JULY

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Constant Field Values

AUGUST

public static final int AUGUST

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Constant Field Values

SEPTEMBER

public static final int SEPTEMBER

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Constant Field Values

OCTOBER

public static final int OCTOBER

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Constant Field Values

NOVEMBER

public static final int NOVEMBER

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Constant Field Values

DECEMBER

public static final int DECEMBER

See Also:

Constant Field Values

MONTHS

public static final java.lang.String[] MONTHS

TIME_UNIT

public static final java.lang.String[] TIME_UNIT

EPOCH_1970

public static final double EPOCH_1970

See Also:

Constant Field Values

EPOCH_0

public static final double EPOCH_0

See Also:

Constant Field Values

SQL_DATE_FORMAT

public static final java.lang.String SQL_DATE_FORMAT

See Also:

Constant Field Values

Constructor Detail

JulianDay

public JulianDay()

JulianCalendar constructor - sets JD for current time

JulianDay

public JulianDay(double jd)

JulianCalendar constructor - sets JD passed as double

Parameters:

jd - double The Julian date

JulianDay

public JulianDay(int yr,
                 int mo,
                 double da)

Constructor to create Julian day given year, month, and decimal day

Parameters:

yr - int

mo - int

da - double

JulianDay

public JulianDay(int yr,
                 int mo,
                 int da)

Construct JulianDate given year, month, and date

Parameters:

yr - int

mo - int

da - int

JulianDay

public JulianDay(int yr,
                 int mo,
                 int da,
                 int hr,
                 int min)

Construct JulianDate given year, month, date, hour and minute

Parameters:

yr - int

mo - int

da - int

JulianDay

public JulianDay(int yr,
                 int mo,
                 int da,
                 int hr,
                 int min,
                 int sec)

Construct JulianDate given year, month, day, hour, minute, and second

Parameters:

yr - int

mo - int

da - int

hr - int

min - int

sec - int

JulianDay

public JulianDay(long timeInMilliSec)

Construct JulianDay from system time in milli-seconds since Jan 1, 1970

JulianDay

public JulianDay(JulianDay cal)

Copy constructor for JulianDate

Parameters:

cal - com.raben.util.JulianDate

JulianDay

public JulianDay(java.lang.String str)

Set JulianDay from sql database compatible date/time string (yyyy-mm-dd hh:mm:ss)

JulianDay

public JulianDay(java.util.Calendar cal)

Construct JulianDate given Calendar as a parameter

Parameters:

cal - java.util.Calendar

Method Detail

add

public void add(int unit,
                double val)

Add specified value in specified time unit to current Julian Date increments next higher field ISSUE - meaning of incrementing YEAR and MONTH by fractional value is not clear since period of a month and year varies, that is ignored. Year is assumed to be 365 days and month is assumed to be 30 days for computing the fractional increment. ISSUE - not thoroughly tested, typically 1-2 second errors may occur due to round-off. Will be refactored "real soon now" :) to utilize BigDecimal internal representation of Julian Day.

Parameters:

unit - int Time unit

val - int Time increment

add

public void add(int unit,
                int val)

Add specified value in specified time unit to current Julian Date increments next higher field ISSUE - meaning of incrementing YEAR and MONTH by fractional value is not clear since period of a month and year varies, that is ignored. Year is assumed to be 365 days and month is assumed to be 30 days for computing the fractional increment. ISSUE - not thoroughly tested, typically 1-2 second errors may occur due to round-off. Will be refactored "real soon now" :) to utilize BigDecimal internal representation of Julian Day.

Parameters:

unit - int Time unit

val - int Time increment

diff

public double diff(JulianDay date)

Returns time difference in days between date specified and the JulianDay of this object (parameter date-this date)

Parameters:

date - com.raben.util.JulianDate

Returns:

double

equals

public boolean equals(double jd)

Returns true if Julian day number is within 0.001 of parameter jd

Parameters:

jd - double

Returns:

boolean

equals

public boolean equals(JulianDay date)

Return true if JulianDates are equal, false otherwise

Parameters:

date - com.raben.util.JulianDate

Returns:

boolean

get

public final int get(int field)

Returns the specified field

Parameters:

field - int The specified field

Returns:

int The field value

getDateTimeStr

public java.lang.String getDateTimeStr()

getJDN

public final double getJDN()

Returns the Julian Date Number as a double

Returns:

double

getMilliSeconds

public long getMilliSeconds()

Returns milli-seconds since Jan 1, 1970

Returns:

long

getMJD

public final double getMJD()

Return the modified Julian date

Returns:

double

getYMD

public java.lang.String getYMD(int leastUnit)

Return date as YYYYMMDDHHSS string with the least unit to be returned specified For example to to return YYYYMMDD specify least unit as JulianDay.DATE

Parameters:

leastUnit - int least unit to be returned

set

public void set(int field,
                double value)

This method sets Julian day or modified Julian day

Parameters:

field - int Field to be changed

value - double The value the field is set to ISSUE - double values are truncated when setting YEAR, MONTH

set

public final void set(int field,
                      int value)

Set various JulianCalendar fields Example: JulianDay jd=new JulianDay(); jd.set(Calendar.YEAR,1999);

Parameters:

field - int The field to be set

value - int The field value

set

public final void set(int year,
                      int month,
                      int date)

Set year, month, and day

Parameters:

year - int

month - int Note - January is 0, December is 11

date - int

set

public final void set(int year,
                      int month,
                      int date,
                      int hour,
                      int minute)

Set year, month,day, hour and minute

Parameters:

year - int

month - int January is 0, Dec is 11

date - int

hour - int

minute - int

set

public final void set(int year,
                      int month,
                      int date,
                      int hour,
                      int minute,
                      int second)

Set year month, day, hour, minute and second

Parameters:

year - int

month - int January is 0, December is 11

date - int

hour - int

minute - int

second - int

set

public final void set(JulianDay jd)

setDateTime

public void setDateTime(java.lang.String str)

Set date/time from string

Parameters:

str - java.lang.String

setEndOfDay

public void setEndOfDay()

set hour to 23, minute and second to 59

setStartOfDay

public void setStartOfDay()

Set hour,minute, and second to 0

setTime

public final void setTime(java.util.Date dat)

Set date from Java Date

setYMD

public void setYMD(java.lang.String str)

Set date from sting in the form YYYYMMDDhhmmss (YYYY=year MM=month DD=day hh=hr mm=min ss=sec)

Parameters:

str - java.lang.String

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object

clone

public java.lang.Object clone()

Return clone of JulianDay object

Overrides:

clone in class java.lang.Object

Returns:

Object;

setDateFormat

public void setDateFormat(java.lang.String formatStr)

Set SimpleDateFormat string ISSUE - only valid after Jan 1, 1970

setDateFormat

public void setDateFormat(java.text.SimpleDateFormat dateFormat)

Set SimpleDateFormat for displaying date/time string

Parameters:

dateFormat - SimpleDateFormat

getTime

public java.util.Date getTime()

Return Java Date

Returns:

Date

update

public void update()

Update JulianDay to current time

getIncrement

public static double getIncrement(int unit,
                                  int incr)

Get increment in days given time unit and increment

Parameters:

unit - Time unit (DATE,HOUR,HOUR_OF_DAY,MINUTE, or SECOND

incr - Time increment in unit specified

Returns:

double Increment in days

Throws:

If - unit is not Julian.DATE, HOUR, HOUR_OF_DAY, MINUTE or SECOND

getCalendar

public java.util.Calendar getCalendar()

Get java Calendar equivalent of Julian Day

Returns:

Calendar