Month (ThreeTen backport for java.time package 1.0.0 API)

java.lang.Object
- java.lang.Enum<Month>
- - java.time.Month

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Month>, TemporalAccessor, TemporalAdjuster
```
public enum Month
extends java.lang.Enum<Month>
implements TemporalAccessor, TemporalAdjuster
```
A month-of-year, such as 'July'.
Month is an enum representing the 12 months of the year - January, February, March, April, May, June, July, August, September, October, November and December.
In addition to the textual enum name, each month-of-year has an int value. The int value follows normal usage and the ISO-8601 standard, from 1 (January) to 12 (December). It is recommended that applications use the enum rather than the int value to ensure code clarity.
Do not use ordinal() to obtain the numeric representation of Month. Use getValue() instead.
This enum represents a common concept that is found in many calendar systems. As such, this enum may be used by any calendar system that has the month-of-year concept defined exactly equivalent to the ISO-8601 calendar system.
Specification for implementors
This is an immutable and thread-safe enum.

Enum Constant Summary

Enum Constants
Enum Constant and Description
`APRIL` The singleton instance for the month of April with 30 days.
`AUGUST` The singleton instance for the month of August with 31 days.
`DECEMBER` The singleton instance for the month of December with 31 days.
`FEBRUARY` The singleton instance for the month of February with 28 days, or 29 in a leap year.
`JANUARY` The singleton instance for the month of January with 31 days.
`JULY` The singleton instance for the month of July with 31 days.
`JUNE` The singleton instance for the month of June with 30 days.
`MARCH` The singleton instance for the month of March with 31 days.
`MAY` The singleton instance for the month of May with 31 days.
`NOVEMBER` The singleton instance for the month of November with 30 days.
`OCTOBER` The singleton instance for the month of October with 31 days.
`SEPTEMBER` The singleton instance for the month of September with 30 days.

Field Summary

Fields
Modifier and Type Field and Description

static TemporalQuery<Month> FROM
Simulate JDK 8 method reference Month::from.

Fields
Modifier and Type	Field and Description
`static TemporalQuery<Month>`	`FROM` Simulate JDK 8 method reference Month::from.

Method Summary

Methods
Modifier and Type	Method and Description
`Temporal`	`adjustInto(Temporal temporal)` Adjusts the specified temporal object to have this month-of-year.
`int`	`firstDayOfYear(boolean leapYear)` Gets the day-of-year corresponding to the first day of this month.
`Month`	`firstMonthOfQuarter()` Gets the month corresponding to the first month of this quarter.
`static Month`	`from(TemporalAccessor temporal)` Obtains an instance of `Month` from a temporal object.
`int`	`get(TemporalField field)` Gets the value of the specified field from this month-of-year as an `int`.
`java.lang.String`	`getDisplayName(TextStyle style, java.util.Locale locale)` Gets the textual representation, such as 'Jan' or 'December'.
`long`	`getLong(TemporalField field)` Gets the value of the specified field from this month-of-year as a `long`.
`int`	`getValue()` Gets the month-of-year `int` value.
`boolean`	`isSupported(TemporalField field)` Checks if the specified field is supported.
`int`	`length(boolean leapYear)` Gets the length of this month in days.
`int`	`maxLength()` Gets the maximum length of this month in days.
`int`	`minLength()` Gets the minimum length of this month in days.
`Month`	`minus(long months)` Returns the month-of-year that is the specified number of months before this one.
`static Month`	`of(int month)` Obtains an instance of `Month` from an `int` value.
`Month`	`plus(long months)` Returns the month-of-year that is the specified number of quarters after this one.
`<R> R`	`query(TemporalQuery<R> query)` Queries this month-of-year using the specified query.
`ValueRange`	`range(TemporalField field)` Gets the range of valid values for the specified field.
`static Month`	`valueOf(java.lang.String name)` Returns the enum constant of this type with the specified name.
`static Month[]`	`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
getClass, notify, notifyAll, wait, wait, wait

- Enum Constant Detail
  - JANUARY
```
public static final Month JANUARY
```
    The singleton instance for the month of January with 31 days. This has the numeric value of 1.
  - FEBRUARY
```
public static final Month FEBRUARY
```
    The singleton instance for the month of February with 28 days, or 29 in a leap year. This has the numeric value of 2.
  - MARCH
```
public static final Month MARCH
```
    The singleton instance for the month of March with 31 days. This has the numeric value of 3.
  - APRIL
```
public static final Month APRIL
```
    The singleton instance for the month of April with 30 days. This has the numeric value of 4.
  - MAY
```
public static final Month MAY
```
    The singleton instance for the month of May with 31 days. This has the numeric value of 5.
  - JUNE
```
public static final Month JUNE
```
    The singleton instance for the month of June with 30 days. This has the numeric value of 6.
  - JULY
```
public static final Month JULY
```
    The singleton instance for the month of July with 31 days. This has the numeric value of 7.
  - AUGUST
```
public static final Month AUGUST
```
    The singleton instance for the month of August with 31 days. This has the numeric value of 8.
  - SEPTEMBER
```
public static final Month SEPTEMBER
```
    The singleton instance for the month of September with 30 days. This has the numeric value of 9.
  - OCTOBER
```
public static final Month OCTOBER
```
    The singleton instance for the month of October with 31 days. This has the numeric value of 10.
  - NOVEMBER
```
public static final Month NOVEMBER
```
    The singleton instance for the month of November with 30 days. This has the numeric value of 11.
  - DECEMBER
```
public static final Month DECEMBER
```
    The singleton instance for the month of December with 31 days. This has the numeric value of 12.
- Field Detail
  - FROM
```
public static final TemporalQuery<Month> FROM
```
    Simulate JDK 8 method reference Month::from.
- Method Detail
  - values
```
public static Month[] 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 (Month c : Month.values())
    System.out.println(c);
```
    Returns:
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static Month valueOf(java.lang.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:
    
    java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
    
    java.lang.NullPointerException - if the argument is null
  - of
```
public static Month of(int month)
```
    Obtains an instance of Month from an int value.
    Month is an enum representing the 12 months of the year. This factory allows the enum to be obtained from the int value. The int value follows the ISO-8601 standard, from 1 (January) to 12 (December).
    
    Parameters:
    month - the month-of-year to represent, from 1 (January) to 12 (December)
    
    Returns:
    the month-of-year, not null
    
    Throws:
    
    DateTimeException - if the month-of-year is invalid
  - from
```
public static Month from(TemporalAccessor temporal)
```
    Obtains an instance of Month from a temporal object.
    A TemporalAccessor represents some form of date and time information. This factory converts the arbitrary temporal object to an instance of Month.
    The conversion extracts the MONTH_OF_YEAR field. The extraction is only permitted if the temporal object has an ISO chronology, or can be converted to a LocalDate.
    This method matches the signature of the functional interface TemporalQuery allowing it to be used in queries via method reference, Month::from.
    
    Parameters:
    temporal - the temporal object to convert, not null
    
    Returns:
    the month-of-year, not null
    
    Throws:
    
    DateTimeException - if unable to convert to a Month
  - getValue
```
public int getValue()
```
    Gets the month-of-year int value.
    The values are numbered following the ISO-8601 standard, from 1 (January) to 12 (December).
    
    Returns:
    the month-of-year, from 1 (January) to 12 (December)
  - getDisplayName
```
public java.lang.String getDisplayName(TextStyle style,
                              java.util.Locale locale)
```
    Gets the textual representation, such as 'Jan' or 'December'.
    This returns the textual name used to identify the month-of-year. The parameters control the length of the returned text and the locale.
    If no textual mapping is found then the numeric value is returned.
    
    Parameters:
    style - the length of the text required, not null
    locale - the locale to use, not null
    
    Returns:
    the text value of the month-of-year, not null
  - isSupported
```
public boolean isSupported(TemporalField field)
```
    Checks if the specified field is supported.
    This checks if this month-of-year can be queried for the specified field. If false, then calling the range and get methods will throw an exception.
    If the field is MONTH_OF_YEAR then this method returns true. All other ChronoField instances will return false.
    If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor) passing this as the argument. Whether the field is supported is determined by the field.
    
    Specified by:
    
    isSupported in interface TemporalAccessor
    
    Parameters:
    field - the field to check, null returns false
    
    Returns:
    true if the field is supported on this month-of-year, false if not
  - range
```
public ValueRange range(TemporalField field)
```
    Gets the range of valid values for the specified field.
    The range object expresses the minimum and maximum valid values for a field. This month is used to enhance the accuracy of the returned range. If it is not possible to return the range, because the field is not supported or for some other reason, an exception is thrown.
    If the field is MONTH_OF_YEAR then the range of the month-of-year, from 1 to 12, will be returned. All other ChronoField instances will throw a DateTimeException.
    If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessor) passing this as the argument. Whether the range can be obtained is determined by the field.
    
    Specified by:
    
    range in interface TemporalAccessor
    
    Parameters:
    field - the field to query the range for, not null
    
    Returns:
    the range of valid values for the field, not null
    
    Throws:
    
    DateTimeException - if the range for the field cannot be obtained
  - get
```
public int get(TemporalField field)
```
    Gets the value of the specified field from this month-of-year as an int.
    This queries this month for the value for the specified field. The returned value will always be within the valid range of values for the field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.
    If the field is MONTH_OF_YEAR then the value of the month-of-year, from 1 to 12, will be returned. All other ChronoField instances will throw a DateTimeException.
    If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.
    
    Specified by:
    
    get in interface TemporalAccessor
    
    Parameters:
    field - the field to get, not null
    
    Returns:
    the value for the field, within the valid range of values
    
    Throws:
    
    DateTimeException - if a value for the field cannot be obtained
    
    DateTimeException - if the range of valid values for the field exceeds an int
    
    DateTimeException - if the value is outside the range of valid values for the field
    
    java.lang.ArithmeticException - if numeric overflow occurs
  - getLong
```
public long getLong(TemporalField field)
```
    Gets the value of the specified field from this month-of-year as a long.
    This queries this month for the value for the specified field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.
    If the field is MONTH_OF_YEAR then the value of the month-of-year, from 1 to 12, will be returned. All other ChronoField instances will throw a DateTimeException.
    If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.
    
    Specified by:
    
    getLong in interface TemporalAccessor
    
    Parameters:
    field - the field to get, not null
    
    Returns:
    the value for the field
    
    Throws:
    
    DateTimeException - if a value for the field cannot be obtained
    
    java.lang.ArithmeticException - if numeric overflow occurs
  - plus
```
public Month plus(long months)
```
    Returns the month-of-year that is the specified number of quarters after this one.
    The calculation rolls around the end of the year from December to January. The specified period may be negative.
    This instance is immutable and unaffected by this method call.
    
    Parameters:
    months - the months to add, positive or negative
    
    Returns:
    the resulting month, not null
  - minus
```
public Month minus(long months)
```
    Returns the month-of-year that is the specified number of months before this one.
    The calculation rolls around the start of the year from January to December. The specified period may be negative.
    This instance is immutable and unaffected by this method call.
    
    Parameters:
    months - the months to subtract, positive or negative
    
    Returns:
    the resulting month, not null
  - length
```
public int length(boolean leapYear)
```
    Gets the length of this month in days.
    This takes a flag to determine whether to return the length for a leap year or not.
    February has 28 days in a standard year and 29 days in a leap year. April, June, September and November have 30 days. All other months have 31 days.
    
    Parameters:
    leapYear - true if the length is required for a leap year
    
    Returns:
    the length of this month in days, from 28 to 31
  - minLength
```
public int minLength()
```
    Gets the minimum length of this month in days.
    February has a minimum length of 28 days. April, June, September and November have 30 days. All other months have 31 days.
    
    Returns:
    the minimum length of this month in days, from 28 to 31
  - maxLength
```
public int maxLength()
```
    Gets the maximum length of this month in days.
    February has a maximum length of 29 days. April, June, September and November have 30 days. All other months have 31 days.
    
    Returns:
    the maximum length of this month in days, from 29 to 31
  - firstDayOfYear
```
public int firstDayOfYear(boolean leapYear)
```
    Gets the day-of-year corresponding to the first day of this month.
    This returns the day-of-year that this month begins on, using the leap year flag to determine the length of February.
    
    Parameters:
    leapYear - true if the length is required for a leap year
    
    Returns:
    the day of year corresponding to the first day of this month, from 1 to 336
  - firstMonthOfQuarter
```
public Month firstMonthOfQuarter()
```
    Gets the month corresponding to the first month of this quarter.
    The year can be divided into four quarters. This method returns the first month of the quarter for the base month. January, February and March return January. April, May and June return April. July, August and September return July. October, November and December return October.
    
    Returns:
    the first month of the quarter corresponding to this month, not null
  - query
```
public <R> R query(TemporalQuery<R> query)
```
    Queries this month-of-year using the specified query.
    This queries this month-of-year using the specified query strategy object. The TemporalQuery object defines the logic to be used to obtain the result. Read the documentation of the query to understand what the result of this method will be.
    The result of this method is obtained by invoking the TemporalQuery.queryFrom(TemporalAccessor) method on the specified query passing this as the argument.
    
    Specified by:
    
    query in interface TemporalAccessor
    
    Type Parameters:
    R - the type of the result
    Parameters:
    query - the query to invoke, not null
    
    Returns:
    the query result, null may be returned (defined by the query)
    
    Throws:
    
    DateTimeException - if unable to query (defined by the query)
    
    java.lang.ArithmeticException - if numeric overflow occurs (defined by the query)
  - adjustInto
```
public Temporal adjustInto(Temporal temporal)
```
    Adjusts the specified temporal object to have this month-of-year.
    This returns a temporal object of the same observable type as the input with the month-of-year changed to be the same as this.
    The adjustment is equivalent to using Temporal.with(TemporalField, long) passing ChronoField.MONTH_OF_YEAR as the field. If the specified temporal object does not use the ISO calendar system then a DateTimeException is thrown.
    In most cases, it is clearer to reverse the calling pattern by using Temporal.with(TemporalAdjuster):
```
   // these two lines are equivalent, but the second approach is recommended
   temporal = thisMonth.adjustInto(temporal);
   temporal = temporal.with(thisMonth);
 
```
    For example, given a date in May, the following are output:
```
   dateInMay.with(JANUARY);    // four months earlier
   dateInMay.with(APRIL);      // one months earlier
   dateInMay.with(MAY);        // same date
   dateInMay.with(JUNE);       // one month later
   dateInMay.with(DECEMBER);   // seven months later
 
```
    This instance is immutable and unaffected by this method call.
    Specified by:
    
    adjustInto in interface TemporalAdjuster
    
    Parameters:
    temporal - the target object to be adjusted, not null
    
    Returns:
    the adjusted object, not null
    
    Throws:
    
    DateTimeException - if unable to make the adjustment
    
    java.lang.ArithmeticException - if numeric overflow occurs

Enum Month

Specification for implementors

Enum Constant Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Enum

Methods inherited from class java.lang.Object

Enum Constant Detail

JANUARY

FEBRUARY

MARCH

APRIL

MAY

JUNE

JULY

AUGUST

SEPTEMBER

OCTOBER

NOVEMBER

DECEMBER

Field Detail

FROM

Method Detail

values

valueOf

of

from

getValue

getDisplayName

isSupported

range

get

getLong

plus

minus

length

minLength

maxLength

firstDayOfYear

firstMonthOfQuarter

query

adjustInto