Class Period
 java.lang.Object

 org.threeten.bp.chrono.ChronoPeriod

 org.threeten.bp.Period

 All Implemented Interfaces:
java.io.Serializable
,TemporalAmount
public final class Period extends ChronoPeriod implements java.io.Serializable
A datebased 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 timebased equivalent to this class.Durations and period differ in their treatment of daylight savings time when added to
ZonedDateTime
. ADuration
will add an exact number of seconds, thus a duration of one day is always exactly 24 hours. By contrast, aPeriod
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 aZonedDateTime
at 18:00 the following day. By contrast, theDuration
will add exactly 24 hours, resulting in aZonedDateTime
at 19:00 the following day (assuming a one hour DST gap).The supported units of a period are
YEARS
,MONTHS
andDAYS
. 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. The normalization assumes a 12 month year, so is not appropriate for all calendar systems.
Specification for implementors
This class is immutable and threadsafe. See Also:
 Serialized Form


Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description Temporal
addTo(Temporal temporal)
Adds this period to the specified temporal object.static Period
between(LocalDate startDate, LocalDate endDate)
Obtains aPeriod
consisting of the number of years, months, and days between two dates.boolean
equals(java.lang.Object obj)
Checks if this period is equal to another period.static Period
from(TemporalAmount amount)
Obtains an instance ofPeriod
from a temporal amount.long
get(TemporalUnit unit)
Gets the value of the requested unit.Chronology
getChronology()
Gets the chronology that defines the meaning of the supported units.int
getDays()
Gets the amount of days of this period.int
getMonths()
Gets the amount of months of this period.java.util.List<TemporalUnit>
getUnits()
Gets the set of units supported by this period.int
getYears()
Gets the amount of years of this period.int
hashCode()
A hash code for this period.boolean
isNegative()
Checks if any of the three units of this period are negative.boolean
isZero()
Checks if all three units of this period are zero.Period
minus(TemporalAmount amountToSubtract)
Returns a copy of this period with the specified amount subtracted.Period
minusDays(long daysToSubtract)
Returns a copy of this period with the specified days subtracted.Period
minusMonths(long monthsToSubtract)
Returns a copy of this period with the specified months subtracted.Period
minusYears(long yearsToSubtract)
Returns a copy of this period with the specified years subtracted.Period
multipliedBy(int scalar)
Returns a new instance with each element in this period multiplied by the specified scalar.Period
negated()
Returns a new instance with each amount in this period negated.Period
normalized()
Returns a copy of this period with the years and months normalized using a 12 month year.static Period
of(int years, int months, int days)
Obtains aPeriod
representing a number of years, months and days.static Period
ofDays(int days)
Obtains aPeriod
representing a number of days.static Period
ofMonths(int months)
Obtains aPeriod
representing a number of months.static Period
ofWeeks(int weeks)
Obtains aPeriod
representing a number of weeks.static Period
ofYears(int years)
Obtains aPeriod
representing a number of years.static Period
parse(java.lang.CharSequence text)
Obtains aPeriod
from a text string such asPnYnMnD
.Period
plus(TemporalAmount amountToAdd)
Returns a copy of this period with the specified amount added.Period
plusDays(long daysToAdd)
Returns a copy of this period with the specified days added.Period
plusMonths(long monthsToAdd)
Returns a copy of this period with the specified months added.Period
plusYears(long yearsToAdd)
Returns a copy of this period with the specified years added.Temporal
subtractFrom(Temporal temporal)
Subtracts this period from the specified temporal object.java.lang.String
toString()
Outputs this period as aString
, such asP6Y3M1D
.long
toTotalMonths()
Gets the total number of months in this period using a 12 month year.Period
withDays(int days)
Returns a copy of this period with the specified amount of days.Period
withMonths(int months)
Returns a copy of this period with the specified amount of months.Period
withYears(int years)
Returns a copy of this period with the specified amount of years.
Methods inherited from class org.threeten.bp.chrono.ChronoPeriod
between




Field Detail

ZERO
public static final Period ZERO
A constant for a period of zero.


Method Detail

ofYears
public static Period ofYears(int years)
Obtains aPeriod
representing a number of years.The resulting period will have the specified years. The months and days units will be zero.
 Parameters:
years
 the number of years, positive or negative Returns:
 the period of years, not null

ofMonths
public static Period ofMonths(int months)
Obtains aPeriod
representing a number of months.The resulting period will have the specified months. The years and days units will be zero.
 Parameters:
months
 the number of months, positive or negative Returns:
 the period of months, not null

ofWeeks
public static Period ofWeeks(int weeks)
Obtains aPeriod
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.
 Parameters:
weeks
 the number of weeks, positive or negative Returns:
 the period of days, not null

ofDays
public static Period ofDays(int days)
Obtains aPeriod
representing a number of days.The resulting period will have the specified days. The years and months units will be zero.
 Parameters:
days
 the number of days, positive or negative Returns:
 the period of days, not null

of
public static Period of(int years, int months, int days)
Obtains aPeriod
representing a number of years, months and days.This creates an instance based on years, months and days.
 Parameters:
years
 the amount of years, may be negativemonths
 the amount of months, may be negativedays
 the amount of days, may be negative Returns:
 the period of years, months and days, not null

from
public static Period from(TemporalAmount amount)
Obtains an instance ofPeriod
from a temporal amount.This obtains a period based on the specified amount. A
TemporalAmount
represents an amount of time, which may be datebased or timebased, which this factory extracts to aPeriod
.The conversion loops around the set of units from the amount and uses the
YEARS
,MONTHS
andDAYS
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. Parameters:
amount
 the temporal amount to convert, not null Returns:
 the equivalent period, not null
 Throws:
DateTimeException
 if unable to convert to aPeriod
java.lang.ArithmeticException
 if the amount of years, months or days exceeds an int

between
public static Period between(LocalDate startDate, LocalDate endDate)
Obtains aPeriod
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 dayofmonth is greater than or equal to the start dayofmonth. For example, from
20100115
to20110318
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.
 Parameters:
startDate
 the start date, inclusive, not nullendDate
 the end date, exclusive, not null Returns:
 the period between this date and the end date, not null
 See Also:
ChronoLocalDate.until(ChronoLocalDate)

parse
public static Period parse(java.lang.CharSequence text)
Obtains aPeriod
from a text string such asPnYnMnD
.This will parse the string produced by
toString()
which is based on the ISO8601 period formatsPnYnMnD
andPnW
.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
.The leading plus/minus sign, and negative values for other units are not part of the ISO8601 standard. In addition, ISO8601 does not permit mixing between the
PnYnMnD
andPnW
formats. Any weekbased 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) "P1Y2M"  Period.of(1, 2, 0) "P1Y2M"  Period.of(1, 2, 0)
 Parameters:
text
 the text to parse, not null Returns:
 the parsed period, not null
 Throws:
DateTimeParseException
 if the text cannot be parsed to a period

getUnits
public java.util.List<TemporalUnit> getUnits()
Description copied from class:ChronoPeriod
Gets the set of units supported by this period.The supported units are chronology specific. They will typically be
YEARS
,MONTHS
andDAYS
. They are returned in order from largest to smallest.This set can be used in conjunction with
ChronoPeriod.get(TemporalUnit)
to access the entire state of the period. Specified by:
getUnits
in interfaceTemporalAmount
 Specified by:
getUnits
in classChronoPeriod
 Returns:
 a list containing the supported units, not null

getChronology
public Chronology getChronology()
Description copied from class:ChronoPeriod
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. Specified by:
getChronology
in classChronoPeriod
 Returns:
 the chronology defining the period, not null

get
public long get(TemporalUnit unit)
Description copied from class:ChronoPeriod
Gets the value of the requested unit.The supported units are chronology specific. They will typically be
YEARS
,MONTHS
andDAYS
. Requesting an unsupported unit will throw an exception. Specified by:
get
in interfaceTemporalAmount
 Specified by:
get
in classChronoPeriod
 Parameters:
unit
 theTemporalUnit
for which to return the value Returns:
 the long value of the unit

isZero
public boolean isZero()
Checks if all three units of this period are zero.A zero period has the value zero for the years, months and days units.
 Overrides:
isZero
in classChronoPeriod
 Returns:
 true if this period is zerolength

isNegative
public boolean isNegative()
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.
 Overrides:
isNegative
in classChronoPeriod
 Returns:
 true if any unit of this period is negative

getYears
public int getYears()
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".
 Returns:
 the amount of years of this period, may be negative

getMonths
public int getMonths()
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".
 Returns:
 the amount of months of this period, may be negative

getDays
public int getDays()
Gets the amount of days of this period.This returns the days unit.
 Returns:
 the amount of days of this period, may be negative

withYears
public Period withYears(int years)
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.
 Parameters:
years
 the years to represent, may be negative Returns:
 a
Period
based on this period with the requested years, not null

withMonths
public Period withMonths(int months)
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.
 Parameters:
months
 the months to represent, may be negative Returns:
 a
Period
based on this period with the requested months, not null

withDays
public Period withDays(int days)
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.
 Parameters:
days
 the days to represent, may be negative Returns:
 a
Period
based on this period with the requested days, not null

plus
public Period plus(TemporalAmount amountToAdd)
Returns a copy of this period with the specified amount added.This input amount is converted to a
Period
usingfrom(TemporalAmount)
. 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.
 Specified by:
plus
in classChronoPeriod
 Parameters:
amountToAdd
 the period to add, not null Returns:
 a
Period
based on this period with the requested period added, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

plusYears
public Period plusYears(long yearsToAdd)
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.
 Parameters:
yearsToAdd
 the years to add, positive or negative Returns:
 a
Period
based on this period with the specified years added, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

plusMonths
public Period plusMonths(long monthsToAdd)
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.
 Parameters:
monthsToAdd
 the months to add, positive or negative Returns:
 a
Period
based on this period with the specified months added, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

plusDays
public Period plusDays(long daysToAdd)
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.
 Parameters:
daysToAdd
 the days to add, positive or negative Returns:
 a
Period
based on this period with the specified days added, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

minus
public Period minus(TemporalAmount amountToSubtract)
Returns a copy of this period with the specified amount subtracted.This input amount is converted to a
Period
usingfrom(TemporalAmount)
. 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.
 Specified by:
minus
in classChronoPeriod
 Parameters:
amountToSubtract
 the period to subtract, not null Returns:
 a
Period
based on this period with the requested period subtracted, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

minusYears
public Period minusYears(long yearsToSubtract)
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.
 Parameters:
yearsToSubtract
 the years to subtract, positive or negative Returns:
 a
Period
based on this period with the specified years subtracted, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

minusMonths
public Period minusMonths(long monthsToSubtract)
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.
 Parameters:
monthsToSubtract
 the years to subtract, positive or negative Returns:
 a
Period
based on this period with the specified months subtracted, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

minusDays
public Period minusDays(long daysToSubtract)
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.
 Parameters:
daysToSubtract
 the months to subtract, positive or negative Returns:
 a
Period
based on this period with the specified days subtracted, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

multipliedBy
public Period multipliedBy(int scalar)
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.
 Specified by:
multipliedBy
in classChronoPeriod
 Parameters:
scalar
 the scalar to multiply by, not null Returns:
 a
Period
based on this period with the amounts multiplied by the scalar, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

negated
public Period negated()
Returns a new instance with each amount in this period negated. Overrides:
negated
in classChronoPeriod
 Returns:
 a
Period
based on this period with the amounts negated, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

normalized
public Period normalized()
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.
 Specified by:
normalized
in classChronoPeriod
 Returns:
 a
Period
based on this period with excess months normalized to years, not null  Throws:
java.lang.ArithmeticException
 if numeric overflow occurs

toTotalMonths
public long toTotalMonths()
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.
 Returns:
 the total number of months in the period, may be negative

addTo
public Temporal addTo(Temporal temporal)
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(TemporalAmount)
.// 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 nonzero amounts will be added. If the datetime 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.
 Specified by:
addTo
in interfaceTemporalAmount
 Specified by:
addTo
in classChronoPeriod
 Parameters:
temporal
 the temporal object to adjust, not null Returns:
 an object of the same type with the adjustment made, not null
 Throws:
DateTimeException
 if unable to addjava.lang.ArithmeticException
 if numeric overflow occurs

subtractFrom
public Temporal subtractFrom(Temporal temporal)
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(TemporalAmount)
.// 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 nonzero, otherwise the combination of years and months is added if nonzero. Finally, any days are added. The calculation will subtract the years, then months, then days. Only nonzero amounts will be subtracted. If the datetime 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.
 Specified by:
subtractFrom
in interfaceTemporalAmount
 Specified by:
subtractFrom
in classChronoPeriod
 Parameters:
temporal
 the temporal object to adjust, not null Returns:
 an object of the same type with the adjustment made, not null
 Throws:
DateTimeException
 if unable to subtractjava.lang.ArithmeticException
 if numeric overflow occurs

equals
public boolean equals(java.lang.Object obj)
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".
 Specified by:
equals
in classChronoPeriod
 Parameters:
obj
 the object to check, null returns false Returns:
 true if this is equal to the other period

hashCode
public int hashCode()
A hash code for this period. Specified by:
hashCode
in classChronoPeriod
 Returns:
 a suitable hash code

toString
public java.lang.String toString()
Outputs this period as aString
, such asP6Y3M1D
.The output will be in the ISO8601 period format. A zero period will be represented as zero days, 'P0D'.
 Specified by:
toString
in classChronoPeriod
 Returns:
 a string representation of this period, not null

