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import {ChronoUnit} from 'js-joda/src/temporal/ChronoUnit.js'
public class | source

ChronoUnit

Extends:

TemporalUnit → ChronoUnit

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 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 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 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 Duration.

Method Summary

Public Methods
public

addTo(temporal: Temporal, amount: Number): Temporal

Returns a copy of the specified temporal object with the specified period added.

public

between(temporal1: Temporal, temporal2: Temporal): Number

Calculates the amount of time between two temporal objects.

public

compareTo(other: TemporalUnit): *

Compares this ChronoUnit to the specified {TemporalUnit}.

public

Gets the estimated duration of this unit in the ISO calendar system.

public

Checks if this unit is a date unit.

public

Checks if the duration of the unit is an estimate.

public

Checks if this unit is supported by the specified temporal object.

public

Checks if this unit is a time unit.

public

toString(): *

Inherited Summary

From class TemporalUnit
public

addTo(dateTime: Temporal, periodToAdd: number): Temporal

Returns a copy of the specified temporal object with the specified period added.

public

between(temporal1: Temporal, temporal2: Temporal): number

Calculates the period in terms of this unit between two temporal objects of the same type.

public

Gets the duration of this unit, which may be an estimate.

public

Checks if this unit is date-based.

public

Checks if the duration of the unit is an estimate.

public

Checks if this unit is supported by the specified temporal object.

public

Checks if this unit is time-based.

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 Temporal#plus:

  // 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, plus, 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 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.

Override:

TemporalUnit#addTo

Params:

NameTypeAttributeDescription
temporal Temporal

the temporal object to adjust, not null

amount Number

the amount of this unit to add, positive or negative

Return:

Temporal

the adjusted temporal object, not null

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 HOURS.between.

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 Temporal#until:

  // 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 UnsupportedTemporalTypeException must be thrown. Implementations must not alter the specified temporal objects.

Override:

TemporalUnit#between

Params:

NameTypeAttributeDescription
temporal1 Temporal

the base temporal object, not null

temporal2 Temporal

the other temporal object, exclusive, not null

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:

NameTypeAttributeDescription
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.

Override:

TemporalUnit#duration

Return:

Duration

the estimated duration of this unit, not null

public isDateBased(): * source

Checks if this unit is a date unit.

Override:

TemporalUnit#isDateBased

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.

Override:

TemporalUnit#isDurationEstimated

Return:

boolean

true if the duration is estimated, false if accurate

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 Temporal#plus.

Override:

TemporalUnit#isSupportedBy

Params:

NameTypeAttributeDescription
temporal Temporal

the temporal object to check, not null

Return:

boolean

true if the unit is supported

public isTimeBased(): * source

Checks if this unit is a time unit.

Override:

TemporalUnit#isTimeBased

Return:

*

true if a time unit, false if a date unit

public toString(): * source

Return:

*