ChronoUnit
Extends:
A standard set of date periods units.
This set of units provide unit-based access to manipulate a date, time or date-time. The standard set of units can be extended by implementing TemporalUnit.
These units are intended to be applicable in multiple calendar systems. For example, most non-ISO calendar systems define units of years, months and days, just with slightly different rules. The documentation of each unit explains how it operates.
Static properties of Class ChronoUnit
ChronoUnit.NANOS
Unit that represents the concept of a nanosecond, the smallest supported unit of time. For the ISO calendar system, it is equal to the 1,000,000,000th part of the second unit.
ChronoUnit.MICROS
Unit that represents the concept of a microsecond. For the ISO calendar system, it is equal to the 1,000,000th part of the second unit.
ChronoUnit.MILLIS
Unit that represents the concept of a millisecond. For the ISO calendar system, it is equal to the 1000th part of the second unit.
ChronoUnit.SECONDS
Unit that represents the concept of a second. For the ISO calendar system, it is equal to the second in the SI system of units, except around a leap-second.
ChronoUnit.MINUTES
Unit that represents the concept of a minute. For the ISO calendar system, it is equal to 60 seconds.
ChronoUnit.HOURS
Unit that represents the concept of an hour. For the ISO calendar system, it is equal to 60 minutes.
ChronoUnit.HALF_DAYS
Unit that represents the concept of half a day, as used in AM/PM. For the ISO calendar system, it is equal to 12 hours.
ChronoUnit.DAYS
Unit that represents the concept of a day. For the ISO calendar system, it is the standard day from midnight to midnight. The estimated duration of a day is {@code 24 Hours}.
When used with other calendar systems it must correspond to the day defined by the rising and setting of the Sun on Earth. It is not required that days begin at midnight - when converting between calendar systems, the date should be equivalent at midday.
ChronoUnit.WEEKS
Unit that represents the concept of a week. For the ISO calendar system, it is equal to 7 days.
When used with other calendar systems it must correspond to an integral number of days.
ChronoUnit.MONTHS
Unit that represents the concept of a month. For the ISO calendar system, the length of the month varies by month-of-year. The estimated duration of a month is one twelfth of {@code 365.2425 Days}.
When used with other calendar systems it must correspond to an integral number of days.
ChronoUnit.YEARS
Unit that represents the concept of a year. For the ISO calendar system, it is equal to 12 months. The estimated duration of a year is {@code 365.2425 Days}.
When used with other calendar systems it must correspond to an integral number of days or months roughly equal to a year defined by the passage of the Earth around the Sun.
ChronoUnit.DECADES
Unit that represents the concept of a decade. For the ISO calendar system, it is equal to 10 years.
When used with other calendar systems it must correspond to an integral number of days and is normally an integral number of years.
ChronoUnit.CENTURIES
Unit that represents the concept of a century. For the ISO calendar system, it is equal to 100 years.
When used with other calendar systems it must correspond to an integral number of days and is normally an integral number of years.
ChronoUnit.MILLENNIA
Unit that represents the concept of a millennium. For the ISO calendar system, it is equal to 1000 years.
When used with other calendar systems it must correspond to an integral number of days and is normally an integral number of years.
ChronoUnit.ERAS
Unit that represents the concept of an era. The ISO calendar system doesn't have eras thus it is impossible to add an era to a date or date-time. The estimated duration of the era is artificially defined as {Year.MAX_VALUE} + 1.
When used with other calendar systems there are no restrictions on the unit.
ChronoUnit.FOREVER
Artificial unit that represents the concept of forever. This is primarily used with TemporalField to represent unbounded fields such as the year or era. The estimated duration of the era is artificially defined as the largest duration supported by {@code Duration}.
Constructor Summary
| Public Constructor | ||
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constructor(name: String, estimatedDuration: Duration) |
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Method Summary
| Public Methods | ||
| public |
Returns a copy of the specified temporal object with the specified period added. |
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Calculates the amount of time between two temporal objects. |
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compareTo(other: TemporalUnit): * Compares this ChronoUnit to the specified {TemporalUnit}. |
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Gets the estimated duration of this unit in the ISO calendar system. |
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isDateBased(): * Checks if this unit is a date unit. |
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Checks if the duration of the unit is an estimate. |
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isSupportedBy(temporal: Temporal): boolean Checks if this unit is supported by the specified temporal object. |
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isTimeBased(): * Checks if this unit is a time unit. |
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| public |
toString(): * |
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Public Constructors
Public Methods
public addTo(temporal: Temporal, amount: Number): Temporal source
Returns a copy of the specified temporal object with the specified period added.
The period added is a multiple of this unit. For example, this method could be used to add "3 days" to a date by calling this method on the instance representing "days", passing the date and the period "3". The period to be added may be negative, which is equivalent to subtraction.
There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use {@link Temporal#plus(long, TemporalUnit)}:
// these two lines are equivalent, but the second approach is recommended temporal = thisUnit.addTo(temporal); temporal = temporal.plus(thisUnit);It is recommended to use the second approach, {@code plus(TemporalUnit)}, as it is a lot clearer to read in code.
Implementations should perform any queries or calculations using the units available in ChronoUnit or the fields available in ChronoField. If the unit is not supported an {@code UnsupportedTemporalTypeException} must be thrown.
Implementations must not alter the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.
Throw:
* |
DateTimeException if the amount cannot be added |
* |
UnsupportedTemporalTypeException if the unit is not supported by the temporal |
public between(temporal1: Temporal, temporal2: Temporal): Number source
Calculates the amount of time between two temporal objects.
This calculates the amount in terms of this unit. The start and end points are supplied as temporal objects and must be of compatible types. The implementation will convert the second type to be an instance of the first type before the calculating the amount. The result will be negative if the end is before the start. For example, the amount in hours between two temporal objects can be calculated using {@code HOURS.between(startTime, endTime)}.
The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the amount in hours between the times 11:30 and 13:29 will only be one hour as it is one minute short of two hours.
There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use {@link Temporal#until(Temporal, TemporalUnit)}:
// these two lines are equivalent between = thisUnit.between(start, end); between = start.until(end, thisUnit);The choice should be made based on which makes the code more readable.
For example, this method allows the number of days between two dates to be calculated:
daysBetween = DAYS.between(start, end); // or alternatively daysBetween = start.until(end, DAYS);
Implementations should perform any queries or calculations using the units available in ChronoUnit or the fields available in ChronoField. If the unit is not supported an {@code UnsupportedTemporalTypeException} must be thrown. Implementations must not alter the specified temporal objects.
Return:
| Number | the amount of time between temporal1 and temporal2 in terms of this unit; positive if temporal2 is later than temporal1, negative if earlier |
Throw:
* |
DateTimeException if the amount cannot be calculated, or the end temporal cannot be converted to the same type as the start temporal |
* |
UnsupportedTemporalTypeException if the unit is not supported by the temporal |
* |
ArithmeticException if numeric overflow occurs |
public compareTo(other: TemporalUnit): * source
Compares this ChronoUnit to the specified {TemporalUnit}.
The comparison is based on the total length of the durations.
Params:
| Name | Type | Attribute | Description |
| other | TemporalUnit | the other unit to compare to, not null |
Return:
| * | the comparator value, negative if less, positive if greater |
public duration(): Duration source
Gets the estimated duration of this unit in the ISO calendar system.
All of the units in this class have an estimated duration. Days vary due to daylight saving time, while months have different lengths.
public isDateBased(): * source
Checks if this unit is a date unit.
Return:
| * | true if a date unit, false if a time unit |
public isDurationEstimated(): boolean source
Checks if the duration of the unit is an estimate.
All time units in this class are considered to be accurate, while all date units in this class are considered to be estimated.
This definition ignores leap seconds, but considers that Days vary due to daylight saving time and months have different lengths.
public isSupportedBy(temporal: Temporal): boolean source
Checks if this unit is supported by the specified temporal object.
This checks that the implementing date-time can add/subtract this unit. This can be used to avoid throwing an exception.
This default implementation derives the value using {@link Temporal#plus(long, TemporalUnit)}.
Params:
| Name | Type | Attribute | Description |
| temporal | Temporal | the temporal object to check, not null |
public isTimeBased(): * source
Checks if this unit is a time unit.
Return:
| * | true if a time unit, false if a date unit |