EpochDays (Time4J-Core 2.2 API)

java.lang.Object
- java.lang.Enum<EpochDays>
- - net.time4j.engine.EpochDays

All Implemented Interfaces:

Serializable, Comparable<EpochDays>, Comparator<ChronoDisplay>, ChronoElement<Long>
```
public enum EpochDays
extends Enum<EpochDays>
implements ChronoElement<Long>
```
Defines elements based on different epoch-related day numbers.

Some day number procedures really use decimal fractions in order to represent wall time fractions in calendar dates (for example julian days). This enum only supports pure date types of type Calendrical and always uses the largest integer which is still smaller than or equal to the decimal fraction in question (mathematically a floor()-function.

Instances of this element class will be automatically registered in any chronology which is compatible to Calendrical.

Author:

Meno Hochschild

See Also:
Calendrical

Enum Constant Summary

Enum Constants
Enum Constant and Description
`ANSI` Count of days relative to the ISO-date [1601-01-01] as day 1.
`EXCEL` Count of days relative to the ISO-date [1900-01-01] as day 1.
`JULIAN_DAY_NUMBER` Count of julian days relative to the the julian calendar date [1st of January 4713 BC] at noon [12:00] as day zero.
`LILIAN_DAY_NUMBER` Count of days relative to gregorian cut-over date [1582-10-15] as day 1.
`MODIFIED_JULIAN_DATE` Count of days relative to the ISO-date [1858-11-17] as day zero.
`RATA_DIE` Count of days relative to the ISO-date [0001-01-01] as day 1.
`UNIX` Bezugspunkt ist der erste Januar 1970 Mitternacht als Tag 0.
`UTC` Reference point is the introduction of UTC on date [1972-01-01] at midnight as day zero.

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`compare(ChronoDisplay o1, ChronoDisplay o2)` Applies an element-orientated sorting of any chronological entities.
`Long`	`getDefaultMaximum()` Returns the default maximum of this element which is not dependent on the chronological context.
`Long`	`getDefaultMinimum()` Returns the default minimum of this element which is not dependent on the chronological context.
`char`	`getSymbol()` Defines the format symbol.
`Class<Long>`	`getType()` Yields the reified value type.
`boolean`	`isDateElement()` This element is a date element.
`boolean`	`isLenient()` Queries if setting of element values is performed in a lenient way.
`boolean`	`isTimeElement()` This element is no wall time element.
`long`	`transform(long amount, EpochDays epoch)` Converts given day number to a day number based on this epoch at reference time of midnight.
`static EpochDays`	`valueOf(String name)` Returns the enum constant of this type with the specified name.
`static EpochDays[]`	`values()` Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

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

Methods inherited from interface net.time4j.engine.ChronoElement
name

Methods inherited from interface java.util.Comparator
equals

- Enum Constant Detail
  - UTC
```
public static final EpochDays UTC
```
    Reference point is the introduction of UTC on date [1972-01-01] at midnight as day zero.
  - UNIX
```
public static final EpochDays UNIX
```
    Bezugspunkt ist der erste Januar 1970 Mitternacht als Tag 0.
    
    Beispiel:
```
  import static net.time4j.Month.FEBRUARY;

  PlainDate date = PlainDate.of(1970, FEBRUARY, 4);
  System.out.println(date.get(EpochDays.UNIX)); // Ausgabe: 34
 
```
    Streng genommen wird die UNIX-Zeit in Sekunden gezählt. Dieses Element benutzt für den Zweck der Datumsumrechnung die Zählung in ganzen Tagen auf der Basis "1 Tag = 86400 Sekunden".
  - MODIFIED_JULIAN_DATE
```
@FormattableElement(format="g")
public static final EpochDays MODIFIED_JULIAN_DATE
```
    Count of days relative to the ISO-date [1858-11-17] as day zero.
    
    Used by astronomers for example.
  - EXCEL
```
public static final EpochDays EXCEL
```
    Count of days relative to the ISO-date [1900-01-01] as day 1.
    
    Used by MS-Excel in Windows operating systems.
  - ANSI
```
public static final EpochDays ANSI
```
    Count of days relative to the ISO-date [1601-01-01] as day 1.
    
    Used by COBOL for example.
  - RATA_DIE
```
public static final EpochDays RATA_DIE
```
    Count of days relative to the ISO-date [0001-01-01] as day 1.
    
    Used by the autors Nachum Dershowitz and Edward M. Reingold in their standard work "CalendarDate Calculations".
  - JULIAN_DAY_NUMBER
```
public static final EpochDays JULIAN_DAY_NUMBER
```
    Count of julian days relative to the the julian calendar date [1st of January 4713 BC] at noon [12:00] as day zero.
    
    The julian epoch date corresponds to the proleptic ISO-date [-4713-11-24]. The ISO-day centered around noon will be taken into account whose associated julian day starts at noon.
  - LILIAN_DAY_NUMBER
```
public static final EpochDays LILIAN_DAY_NUMBER
```
    Count of days relative to gregorian cut-over date [1582-10-15] as day 1.
- Method Detail
  - values
```
public static EpochDays[] 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 (EpochDays c : EpochDays.values())
    System.out.println(c);
```
    Returns:
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static EpochDays 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
  - transform
```
public long transform(long amount,
             EpochDays epoch)
```
    Converts given day number to a day number based on this epoch at reference time of midnight.
    
    Parameters:
    amount - count of days relative to given epoch at noon
    epoch - epoch reference
    
    Returns:
    count of days relative to this epoch
  - getType
```
public Class<Long> getType()
```
    Description copied from interface: ChronoElement
    
    Yields the reified value type.
    
    Specified by:
    
    getType in interface ChronoElement<Long>
    
    Returns:
    type of associated values
  - getSymbol
```
public char getSymbol()
```
    Defines the format symbol.
    
    Specified by:
    
    getSymbol in interface ChronoElement<Long>
    
    Returns:
    "g" if MODIFIED_JULIAN_DATE else ASCII-0
    See Also:
    FormattableElement
  - compare
```
public int compare(ChronoDisplay o1,
          ChronoDisplay o2)
```
    Description copied from interface: ChronoElement
    
    Applies an element-orientated sorting of any chronological entities.
    
    The value type V is usually a subtype of the interface Comparable so that this method will usually be based on the expression o1.get(this).compareTo(o2.get(this)). In other words, this method compares the element values of given chronological entities. It is even permitted to compare entities of different chronological types as long as the entities both support this element.
    
    It should be noted however that a element value comparison does often not induce any temporal (complete) order. Counter examples are the year of gregorian BC-era (reversed temporal order before Jesu birth) or the clock display of hours (12 is indeed the begin at midnight).
    
    Specified by:
    
    compare in interface Comparator<ChronoDisplay>
    
    Specified by:
    
    compare in interface ChronoElement<Long>
    
    Parameters:
    o1 - the first object to be compared
    o2 - the second object to be compared
    
    Returns:
    a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second
  - getDefaultMinimum
```
public Long getDefaultMinimum()
```
    Description copied from interface: ChronoElement
    
    Returns the default minimum of this element which is not dependent on the chronological context.
    
    Note: This minimum does not necessarily define a minimum for all possible circumstances but only the default minimum under normal conditions such that the default minimum always exists and can be used as prototypical value. An example is the start of day which is usually midnight in ISO-8601 and can only deviate in specialized timezone context.
    
    Specified by:
    
    getDefaultMinimum in interface ChronoElement<Long>
    
    Returns:
    default minimum value of element
    See Also:
    ChronoElement.getDefaultMaximum()
  - getDefaultMaximum
```
public Long getDefaultMaximum()
```
    Description copied from interface: ChronoElement
    
    Returns the default maximum of this element which is not dependent on the chronological context.
    
    Note: This maximum does not necessarily define a maximum for all possible circumstances but only the default maximum under normal conditions. An example is the second of minute whose default maximum is 59 while the largest maximum can be 60 in context of UTC-leapseconds.
    
    Specified by:
    
    getDefaultMaximum in interface ChronoElement<Long>
    
    Returns:
    default maximum value of element
    See Also:
    ChronoElement.getDefaultMinimum()
  - isDateElement
```
public boolean isDateElement()
```
    This element is a date element.
    
    Specified by:
    
    isDateElement in interface ChronoElement<Long>
    
    Returns:
    true
    See Also:
    ChronoElement.isTimeElement()
  - isTimeElement
```
public boolean isTimeElement()
```
    This element is no wall time element.
    
    Specified by:
    
    isTimeElement in interface ChronoElement<Long>
    
    Returns:
    false
    See Also:
    ChronoElement.isDateElement()
  - isLenient
```
public boolean isLenient()
```
    Description copied from interface: ChronoElement
    
    Queries if setting of element values is performed in a lenient way.
    
    Specified by:
    
    isLenient in interface ChronoElement<Long>
    
    Returns:
    true if lenient else false (standard)
    See Also:
    ElementRule.withValue(T, V, boolean)

Enum EpochDays

Enum Constant Summary

Method Summary

Methods inherited from class java.lang.Enum

Methods inherited from class java.lang.Object

Methods inherited from interface net.time4j.engine.ChronoElement

Methods inherited from interface java.util.Comparator

Enum Constant Detail

UTC

UNIX

MODIFIED_JULIAN_DATE

EXCEL

ANSI

RATA_DIE

JULIAN_DAY_NUMBER

LILIAN_DAY_NUMBER

Method Detail

values

valueOf

transform

getType

getSymbol

compare

getDefaultMinimum

getDefaultMaximum

isDateElement

isTimeElement

isLenient