JulianDate (Jodd API Documentation)

java.lang.Object
- jodd.util.JulianDate

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable
```
public class JulianDate
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable
```
Julian Date stamp, for high precision calculations. Julian date is a real number and it basically consist of two parts: integer and fraction. Integer part carries date information, fraction carries time information.
The Julian day or Julian day number (JDN) is the (integer) number of days that have elapsed since Monday, January 1, 4713 BC in the proleptic Julian calendar 1. That day is counted as Julian day zero. Thus the multiples of 7 are Mondays. Negative values can also be used.
The Julian Date (JD) is the number of days (with decimal fraction of the day) that have elapsed since 12 noon Greenwich Mean Time (UT or TT) of that day. Rounding to the nearest integer gives the Julian day number.
For calculations that will have time precision of 1e-3 seconds, both fraction and integer part must have enough digits in it. The problem is that integer part is big and, on the other hand fractional is small, and since final julian date is a sum of this two values, some fraction numerals may be lost. Therefore, for higher precision both fractional and integer part of julian date real number has to be preserved.
This class stores the unmodified fraction part, but not all digits are significant! For 1e-3 seconds precision, only 8 digits after the decimal point are significant.

See Also:

TimeUtil, Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected double`	`fraction` Fraction part of the Julian Date (JD).
`protected int`	`integer` Integer part of the Julian Date (JD).
`static JulianDate`	`JD_1970` Julian Date for 1970-01-01T00:00:00 (Thursday).
`static JulianDate`	`JD_2001` Julian Date for 2001-01-01T00:00:00 (Monday).

Constructor Summary

Constructors
Constructor and Description
`JulianDate(java.math.BigDecimal bd)` Creates JD from `BigDecimal`.
`JulianDate(double jd)` Creates JD from a `double`.
`JulianDate(int i, double f)` Creates JD from both integer and fractional part using normalization.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`JulianDate`	`add(double delta)` Adds a double to current instance.
`JulianDate`	`add(JulianDate jds)` Adds a JD to current instance.
`protected JulianDate`	`clone()`
`int`	`daysBetween(JulianDate otherDate)` Calculates the number of days between two dates.
`int`	`daysSpan(JulianDate otherDate)` Returns span between two days.
`double`	`doubleValue()` Returns `double` value of JD.
`boolean`	`equals(java.lang.Object object)`
`double`	`getFraction()` Returns the fraction part of Julian Date (JD).
`int`	`getInteger()` Returns integer part of the Julian Date (JD).
`int`	`getJulianDayNumber()` Returns JDN.
`JulianDate`	`getModifiedJulianDate()` Returns Modified Julian Date (MJD), where date starts from midnight rather than noon.
`JulianDate`	`getReducedJulianDate()` Returns Reduced Julian Date (RJD), used by astronomers.
`int`	`getSignificantFraction()` Calculates and returns significant fraction only as an int.
`JulianDate`	`getTruncatedJulianDate()` Returns Truncated Julian Day (TJD), introduced by NASA for the space program.
`int`	`hashCode()`
`static JulianDate`	`of(double value)`
`static JulianDate`	`of(int i, double f)`
`static JulianDate`	`of(int year, int month, int day, int hour, int minute, int second, int millisecond)`
`static JulianDate`	`of(java.time.LocalDate localDate)`
`static JulianDate`	`of(java.time.LocalDateTime localDateTime)`
`static JulianDate`	`of(long milliseconds)`
`JulianDate`	`sub(double delta)` Subtracts a double from current instance.
`JulianDate`	`sub(JulianDate jds)` Subtracts a JD from current instance.
`java.math.BigDecimal`	`toBigDecimal()` Returns `BigDecimal` value of JD.
`java.time.LocalDateTime`	`toLocalDateTime()`
`long`	`toMilliseconds()` Converts to milliseconds.
`java.lang.String`	`toString()` Returns string representation of JD.

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - JD_1970
```
public static final JulianDate JD_1970
```
    Julian Date for 1970-01-01T00:00:00 (Thursday).
  - JD_2001
```
public static final JulianDate JD_2001
```
    Julian Date for 2001-01-01T00:00:00 (Monday).
  - integer
```
protected int integer
```
    Integer part of the Julian Date (JD).
  - fraction
```
protected double fraction
```
    Fraction part of the Julian Date (JD). Should be always in [0.0, 1.0) range.
- Constructor Detail
  - JulianDate
```
public JulianDate(double jd)
```
    Creates JD from a double.
  - JulianDate
```
public JulianDate(int i,
                  double f)
```
    Creates JD from both integer and fractional part using normalization. Normalization occurs when fractional part is out of range.
    
    Parameters:
    
    i - integer part
    
    f - fractional part should be in range [0.0, 1.0)
    
    See Also:
    
    set(int, double)
  - JulianDate
```
public JulianDate(java.math.BigDecimal bd)
```
    Creates JD from BigDecimal.
- Method Detail
  - of
```
public static JulianDate of(double value)
```
  - of
```
public static JulianDate of(java.time.LocalDateTime localDateTime)
```
  - of
```
public static JulianDate of(java.time.LocalDate localDate)
```
  - of
```
public static JulianDate of(long milliseconds)
```
  - of
```
public static JulianDate of(int i,
                            double f)
```
  - of
```
public static JulianDate of(int year,
                            int month,
                            int day,
                            int hour,
                            int minute,
                            int second,
                            int millisecond)
```
  - getInteger
```
public int getInteger()
```
    Returns integer part of the Julian Date (JD).
  - getFraction
```
public double getFraction()
```
    Returns the fraction part of Julian Date (JD). Returned value is always in [0.0, 1.0) range.
  - getSignificantFraction
```
public int getSignificantFraction()
```
    Calculates and returns significant fraction only as an int.
  - getJulianDayNumber
```
public int getJulianDayNumber()
```
    Returns JDN. Note that JDN is not equal to integer. It is calculated by rounding to the nearest integer.
  - doubleValue
```
public double doubleValue()
```
    Returns double value of JD. CAUTION: double values may not be suit for precision math due to loss of precision.
  - toBigDecimal
```
public java.math.BigDecimal toBigDecimal()
```
    Returns BigDecimal value of JD.
  - toString
```
public java.lang.String toString()
```
    Returns string representation of JD.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    julian integer as string
  - toMilliseconds
```
public long toMilliseconds()
```
    Converts to milliseconds.
  - toLocalDateTime
```
public java.time.LocalDateTime toLocalDateTime()
```
  - add
```
public JulianDate add(JulianDate jds)
```
    Adds a JD to current instance.
  - add
```
public JulianDate add(double delta)
```
    Adds a double to current instance.
  - sub
```
public JulianDate sub(JulianDate jds)
```
    Subtracts a JD from current instance.
  - sub
```
public JulianDate sub(double delta)
```
    Subtracts a double from current instance.
  - daysBetween
```
public int daysBetween(JulianDate otherDate)
```
    Calculates the number of days between two dates. Returned value is always positive.
  - daysSpan
```
public int daysSpan(JulianDate otherDate)
```
    Returns span between two days. Returned value may be positive (when this date is after the provided one) or negative (when comparing to future date).
  - equals
```
public boolean equals(java.lang.Object object)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - clone
```
protected JulianDate clone()
```
    Overrides:
    
    clone in class java.lang.Object
  - getReducedJulianDate
```
public JulianDate getReducedJulianDate()
```
    Returns Reduced Julian Date (RJD), used by astronomers. RJD = JD − 2400000
  - getModifiedJulianDate
```
public JulianDate getModifiedJulianDate()
```
    Returns Modified Julian Date (MJD), where date starts from midnight rather than noon. RJD = JD − 2400000.5
  - getTruncatedJulianDate
```
public JulianDate getTruncatedJulianDate()
```
    Returns Truncated Julian Day (TJD), introduced by NASA for the space program. TJD began at midnight at the beginning of May 24, 1968 (Friday).

Class JulianDate

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

JD_1970

JD_2001

integer

fraction

Constructor Detail

JulianDate

JulianDate

JulianDate

Method Detail

of

of

of

of

of

of

getInteger

getFraction

getSignificantFraction

getJulianDayNumber

doubleValue

toBigDecimal

toString

toMilliseconds

toLocalDateTime

add

add

sub

sub

daysBetween

daysSpan

equals

hashCode

clone

getReducedJulianDate

getModifiedJulianDate

getTruncatedJulianDate