Period
Extends:
A date-based amount of time, such as '2 years, 3 months and 4 days'.
This class models a quantity or amount of time in terms of years, months and days. See Duration for the time-based equivalent to this class.
Durations and period differ in their treatment of daylight savings time when added to ZonedDateTime. A Duration will add an exact number of seconds, thus a duration of one day is always exactly 24 hours. By contrast, a Period will add a conceptual day, trying to maintain the local time.
For example, consider adding a period of one day and a duration of one day to 18:00 on the evening before a daylight savings gap. The Period will add the conceptual day and result in a ZonedDateTime at 18:00 the following day. By contrast, the Duration will add exactly 24 hours, resulting in a ZonedDateTime at 19:00 the following day (assuming a one hour DST gap).
The supported units of a period are ChronoUnit#YEARS, ChronoUnit#MONTHS and ChronoUnit#DAYS. All three fields are always present, but may be set to zero.
The period may be used with any calendar system. The meaning of a 'year' or 'month' is only applied when the object is added to a date.
The period is modeled as a directed amount of time, meaning that individual parts of the period may be negative.
The months and years fields may be normalized (see normalized). The normalization assumes a 12 month year, so is not appropriate for all calendar systems.
Static properties of Class Period
Period.ZERO
A constant for a period of zero.
Static Method Summary
Static Public Methods | ||
public static |
Obtains a Period consisting of the number of years, months, and days between two dates. |
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public static |
Creates an instance. |
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public static |
from(amount: TemporalAmount): Period Obtains an instance of Period from a temporal amount. |
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public static |
Obtains a Period representing a number of years, months and days. |
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public static |
Obtains a Period representing a number of days. |
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public static |
Obtains a Period representing a number of months. |
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public static |
Obtains a Period representing a number of weeks. |
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public static |
Obtains a Period representing a number of years. |
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public static |
Obtains a Period from a text string such as PnYnMnD. |
Method Summary
Public Methods | ||
public |
Adds this period to the specified temporal object. |
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Gets the chronology that defines the meaning of the supported units. |
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days(): number Gets the amount of days of this period. |
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equals(obj: *): boolean Checks if this period is equal to another period. |
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get(unit: TemporalUnit): number Gets the value of the requested unit. |
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hashCode(): number A hash code for this period. |
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isNegative(): boolean Checks if any of the three units of this period are negative. |
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isZero(): boolean Checks if all three units of this period are zero. |
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minus(amountToSubtract: TemporalAmount): Period Returns a copy of this period with the specified amount subtracted. |
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Returns a copy of this period with the specified days subtracted. |
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minusMonths(monthsToSubtract: number): Period Returns a copy of this period with the specified months subtracted. |
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minusYears(yearsToSubtract: number): Period Returns a copy of this period with the specified years subtracted. |
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months(): number Gets the amount of months of this period. |
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multipliedBy(scalar: number): Period Returns a new instance with each element in this period multiplied by the specified scalar. |
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Returns a new instance with each amount in this period negated. |
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normalized(): Period Returns a copy of this period with the years and months normalized using a 12 month year. |
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plus(amountToAdd: TemporalAmount): Period Returns a copy of this period with the specified amount added. |
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Returns a copy of this period with the specified days added. |
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plusMonths(monthsToAdd: number): Period Returns a copy of this period with the specified months added. |
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Returns a copy of this period with the specified years added. |
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subtractFrom(temporal: Temporal): Temporal Subtracts this period from the specified temporal object. |
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toJSON(): string |
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toString(): string Outputs this period as a string, such as P6Y3M1D. |
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toTotalMonths(): number Gets the total number of months in this period using a 12 month year. |
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units(): ChronoUnit[] Gets the list of units, from largest to smallest, that fully define this amount. |
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Returns a copy of this period with the specified amount of days. |
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withMonths(months: number): Period Returns a copy of this period with the specified amount of months. |
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Returns a copy of this period with the specified amount of years. |
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years(): number Gets the amount of years of this period. |
Inherited Summary
From class TemporalAmount | ||
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Adds to the specified temporal object. |
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get(unit: TemporalUnit): number Returns the value of the requested unit. |
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subtractFrom(temporal: Temporal): Temporal Subtracts this object from the specified temporal object. |
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units(): TemporalUnit[] Returns the list of units uniquely defining the value of this TemporalAmount. |
Static Public Methods
public static between(startDate: LocalDate, endDate: LocalDate): Period source
Obtains a Period consisting of the number of years, months, and days between two dates.
The start date is included, but the end date is not.
The period is calculated by removing complete months, then calculating
the remaining number of days, adjusting to ensure that both have the same sign.
The number of months is then split into years and months based on a 12 month year.
A month is considered if the end day-of-month is greater than or equal to the start day-of-month.
For example, from 2010-01-15
to 2011-03-18
is one year, two months and three days.
The result of this method can be a negative period if the end is before the start. The negative sign will be the same in each of year, month and day.
public static create(years: number, months: number, days: number): Duration source
Creates an instance.
Params:
Name | Type | Attribute | Description |
years | number | the amount |
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months | number | the amount |
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days | number | the amount |
public static from(amount: TemporalAmount): Period source
Obtains an instance of Period from a temporal amount.
This obtains a period based on the specified amount. A TemporalAmount represents an - amount of time, which may be date-based or time-based, which this factory extracts to a Period.
The conversion loops around the set of units from the amount and uses the ChronoUnit#YEARS, ChronoUnit#MONTHS and ChronoUnit#DAYS units to create a period. If any other units are found then an exception is thrown.
If the amount is a ChronoPeriod then it must use the ISO chronology.
Params:
Name | Type | Attribute | Description |
amount | TemporalAmount | the temporal amount to convert, not null |
Throw:
* |
DateTimeException if unable to convert to a Period |
* |
ArithmeticException if the amount of years, months or days exceeds an int |
public static of(years: number, months: number, days: number): Period source
Obtains a Period representing a number of years, months and days.
This creates an instance based on years, months and days.
Params:
Name | Type | Attribute | Description |
years | number |
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the amount of years, may be negative |
months | number |
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the amount of months, may be negative |
days | number |
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the amount of days, may be negative |
public static ofDays(days: number): Period source
Obtains a Period representing a number of days.
The resulting period will have the specified days. The years and months units will be zero.
Params:
Name | Type | Attribute | Description |
days | number | the number of days, positive or negative |
public static ofMonths(months: number): Period source
Obtains a Period representing a number of months.
The resulting period will have the specified months. The years and days units will be zero.
Params:
Name | Type | Attribute | Description |
months | number | the number of months, positive or negative |
public static ofWeeks(weeks: number): Period source
Obtains a Period representing a number of weeks.
The resulting period will have days equal to the weeks multiplied by seven. The years and months units will be zero.
Params:
Name | Type | Attribute | Description |
weeks | number | the number of weeks, positive or negative |
public static ofYears(years: number): Period source
Obtains a Period representing a number of years.
The resulting period will have the specified years. The months and days units will be zero.
Params:
Name | Type | Attribute | Description |
years | number | the number of years, positive or negative |
public static parse(text: string): Period source
Obtains a Period from a text string such as PnYnMnD.
This will parse the string produced by toString which is based on the ISO-8601 period formats PnYnMnD and PnW.
The string starts with an optional sign, denoted by the ASCII negative
or positive symbol. If negative, the whole period is negated.
The ASCII letter 'P' is next in upper or lower case.
There are then four sections, each consisting of a number and a suffix.
At least one of the four sections must be present.
The sections have suffixes in ASCII of 'Y', 'M', 'W' and 'D' for
years, months, weeks and days, accepted in upper or lower case.
The suffixes must occur in order.
The number part of each section must consist of ASCII digits.
The number may be prefixed by the ASCII negative or positive symbol.
The number must parse to an int
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The leading plus/minus sign, and negative values for other units are not part of the ISO-8601 standard. In addition, ISO-8601 does not permit mixing between the PnYnMnD and PnW formats. Any week-based input is multiplied by 7 and treated as a number of days.
For example, the following are valid inputs:
'P2Y' -- Period.ofYears(2) 'P3M' -- Period.ofMonths(3) 'P4W' -- Period.ofWeeks(4) 'P5D' -- Period.ofDays(5) 'P1Y2M3D' -- Period.of(1, 2, 3) 'P1Y2M3W4D' -- Period.of(1, 2, 25) 'P-1Y2M' -- Period.of(-1, 2, 0) '-P1Y2M' -- Period.of(-1, -2, 0)
Params:
Name | Type | Attribute | Description |
text | string | the text to parse, not null |
Throw:
* |
DateTimeParseException if the text cannot be parsed to a period |
Public Methods
public addTo(temporal: Temporal): Temporal source
Adds this period to the specified temporal object.
This returns a temporal object of the same observable type as the input with this period added.
In most cases, it is clearer to reverse the calling pattern by using Temporal#plus.
// these two lines are equivalent, but the second approach is recommended dateTime = thisPeriod.addTo(dateTime); dateTime = dateTime.plus(thisPeriod);
The calculation will add the years, then months, then days. Only non-zero amounts will be added. If the date-time has a calendar system with a fixed number of months in a year, then the years and months will be combined before being added.
This instance is immutable and unaffected by this method call.
Override:
TemporalAmount#addToParams:
Name | Type | Attribute | Description |
temporal | Temporal | the temporal object to adjust, not null |
Throw:
* |
DateTimeException if unable to add |
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ArithmeticException if numeric overflow occurs |
public chronology(): IsoChronology source
Gets the chronology that defines the meaning of the supported units.
The period is defined by the chronology. It controls the supported units and restricts addition/subtraction to ChronoLocalDate instances of the same chronology.
public days(): number source
Gets the amount of days of this period.
This returns the days unit.
Return:
number | the amount of days of this period, may be negative |
public equals(obj: *): boolean source
Checks if this period is equal to another period.
The comparison is based on the amounts held in the period. To be equal, the years, months and days units must be individually equal. Note that this means that a period of '15 Months' is not equal to a period of '1 Year and 3 Months'.
Params:
Name | Type | Attribute | Description |
obj | * | the object to check, null returns false |
Return:
boolean | true if this is equal to the other period |
public get(unit: TemporalUnit): number source
Gets the value of the requested unit.
The supported units are chronology specific. They will typically be ChronoUnit#YEARS, ChronoUnit#MONTHS and ChronoUnit#DAYS. Requesting an unsupported unit will throw an exception.
Override:
TemporalAmount#getParams:
Name | Type | Attribute | Description |
unit | TemporalUnit | the TemporalUnit for which to return the value |
Return:
number | the long value of the unit |
Throw:
* |
DateTimeException if the unit is not supported |
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UnsupportedTemporalTypeException if the unit is not supported |
public isNegative(): boolean source
Checks if any of the three units of this period are negative.
This checks whether the years, months or days units are less than zero.
Return:
boolean | true if any unit of this period is negative |
public isZero(): boolean source
Checks if all three units of this period are zero.
A zero period has the value zero for the years, months and days units.
Return:
boolean | true if this period is zero-length |
public minus(amountToSubtract: TemporalAmount): Period source
Returns a copy of this period with the specified amount subtracted.
This input amount is converted to a Period using from. This operates separately on the years, months and days.
For example, '1 year, 6 months and 3 days' minus '2 years, 2 months and 2 days' returns '-1 years, 4 months and 1 day'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
amountToSubtract | TemporalAmount | the period to subtract, not null |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public minusDays(daysToSubtract: number): Period source
Returns a copy of this period with the specified days subtracted.
This subtracts the amount from the days unit in a copy of this period. The years and months units are unaffected. For example, '1 year, 6 months and 3 days' minus 2 days returns '1 year, 6 months and 1 day'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
daysToSubtract | number | the months to subtract, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public minusMonths(monthsToSubtract: number): Period source
Returns a copy of this period with the specified months subtracted.
This subtracts the amount from the months unit in a copy of this period. The years and days units are unaffected. For example, '1 year, 6 months and 3 days' minus 2 months returns '1 year, 4 months and 3 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
monthsToSubtract | number | the years to subtract, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public minusYears(yearsToSubtract: number): Period source
Returns a copy of this period with the specified years subtracted.
This subtracts the amount from the years unit in a copy of this period. The months and days units are unaffected. For example, '1 year, 6 months and 3 days' minus 2 years returns '-1 years, 6 months and 3 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
yearsToSubtract | number | the years to subtract, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public months(): number source
Gets the amount of months of this period.
This returns the months unit.
The months unit is not normalized with the years unit. This means that a period of '15 months' is different to a period of '1 year and 3 months'.
Return:
number | the amount of months of this period, may be negative |
public multipliedBy(scalar: number): Period source
Returns a new instance with each element in this period multiplied by the specified scalar.
This simply multiplies each field, years, months, days and normalized time, by the scalar. No normalization is performed.
Params:
Name | Type | Attribute | Description |
scalar | number | the scalar to multiply by, not null |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public negated(): Period source
Returns a new instance with each amount in this period negated.
Throw:
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ArithmeticException if numeric overflow occurs |
public normalized(): Period source
Returns a copy of this period with the years and months normalized using a 12 month year.
This normalizes the years and months units, leaving the days unit unchanged. The months unit is adjusted to have an absolute value less than 11, with the years unit being adjusted to compensate. For example, a period of '1 Year and 15 months' will be normalized to '2 years and 3 months'.
The sign of the years and months units will be the same after normalization. For example, a period of '1 year and -25 months' will be normalized to '-1 year and -1 month'.
This normalization uses a 12 month year which is not valid for all calendar systems.
This instance is immutable and unaffected by this method call.
Throw:
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ArithmeticException if numeric overflow occurs |
public plus(amountToAdd: TemporalAmount): Period source
Returns a copy of this period with the specified amount added.
This input amount is converted to a Period using from. This operates separately on the years, months and days.
For example, '1 year, 6 months and 3 days' plus '2 years, 2 months and 2 days' returns '3 years, 8 months and 5 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
amountToAdd | TemporalAmount | the period to add, not null |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public plusDays(daysToAdd: number): Period source
Returns a copy of this period with the specified days added.
This adds the amount to the days unit in a copy of this period. The years and months units are unaffected. For example, '1 year, 6 months and 3 days' plus 2 days returns '1 year, 6 months and 5 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
daysToAdd | number | the days to add, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public plusMonths(monthsToAdd: number): Period source
Returns a copy of this period with the specified months added.
This adds the amount to the months unit in a copy of this period. The years and days units are unaffected. For example, '1 year, 6 months and 3 days' plus 2 months returns '1 year, 8 months and 3 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
monthsToAdd | number | the months to add, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public plusYears(yearsToAdd: number): Period source
Returns a copy of this period with the specified years added.
This adds the amount to the years unit in a copy of this period. The months and days units are unaffected. For example, '1 year, 6 months and 3 days' plus 2 years returns '3 years, 6 months and 3 days'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
yearsToAdd | number | the years to add, positive or negative |
Throw:
* |
ArithmeticException if numeric overflow occurs |
public subtractFrom(temporal: Temporal): Temporal source
Subtracts this period from the specified temporal object.
This returns a temporal object of the same observable type as the input with this period subtracted.
In most cases, it is clearer to reverse the calling pattern by using Temporal#minus.
// these two lines are equivalent, but the second approach is recommended dateTime = thisPeriod.subtractFrom(dateTime); dateTime = dateTime.minus(thisPeriod);
The calculation operates as follows. First, the chronology of the temporal is checked to ensure it is ISO chronology or null. Second, if the months are zero, the years are added if non-zero, otherwise the combination of years and months is added if non-zero. Finally, any days are added.
The calculation will subtract the years, then months, then days. Only non-zero amounts will be subtracted. If the date-time has a calendar system with a fixed number of months in a year, then the years and months will be combined before being subtracted.
This instance is immutable and unaffected by this method call.
Override:
TemporalAmount#subtractFromParams:
Name | Type | Attribute | Description |
temporal | Temporal | the temporal object to adjust, not null |
Throw:
* |
DateTimeException if unable to subtract |
* |
ArithmeticException if numeric overflow occurs |
public toString(): string source
Outputs this period as a string, such as P6Y3M1D.
The output will be in the ISO-8601 period format. A zero period will be represented as zero days, 'P0D'.
Return:
string | a string representation of this period, not null |
public toTotalMonths(): number source
Gets the total number of months in this period using a 12 month year.
This returns the total number of months in the period by multiplying the number of years by 12 and adding the number of months.
This uses a 12 month year which is not valid for all calendar systems.
This instance is immutable and unaffected by this method call.
Return:
number | the total number of months in the period, may be negative |
public units(): ChronoUnit[] source
Gets the list of units, from largest to smallest, that fully define this amount.
Override:
TemporalAmount#unitspublic withDays(days: number): Period source
Returns a copy of this period with the specified amount of days.
This sets the amount of the days unit in a copy of this period. The years and months units are unaffected.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
days | number | the days to represent, may be negative |
public withMonths(months: number): Period source
Returns a copy of this period with the specified amount of months.
This sets the amount of the months unit in a copy of this period. The years and days units are unaffected.
The months unit is not normalized with the years unit. This means that a period of '15 months' is different to a period of '1 year and 3 months'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
months | number | the months to represent, may be negative |
public withYears(years: number): Period source
Returns a copy of this period with the specified amount of years.
This sets the amount of the years unit in a copy of this period. The months and days units are unaffected.
The months unit is not normalized with the years unit. This means that a period of '15 months' is different to a period of '1 year and 3 months'.
This instance is immutable and unaffected by this method call.
Params:
Name | Type | Attribute | Description |
years | number | the years to represent, may be negative |
public years(): number source
Gets the amount of years of this period.
This returns the years unit.
The months unit is not normalized with the years unit. This means that a period of '15 months' is different to a period of '1 year and 3 months'.
Return:
number | the amount of years of this period, may be negative |