DateFormat.Field (Java Platform SE 8 )
Keywords: java.text.DateFormat.Field class
Date: 2026-03-29

compact1, compact2, compact3
java.text

## Class DateFormat.Field

- java.lang.Object
- - java.text.AttributedCharacterIterator.Attribute
  - - java.text.Format.Field
    - - java.text.DateFormat.Field

- All Implemented Interfaces:
    Serializable
  Enclosing class:
    DateFormat

      public static class DateFormat.Field
      extends Format.Field

  Defines constants that are used as attribute keys in the `AttributedCharacterIterator` returned from `DateFormat.formatToCharacterIterator` and as field identifiers in `FieldPosition`.

  The class also provides two methods to map between its constants and the corresponding Calendar constants.

  Since:
    1.4
  See Also:
    `Calendar`, Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static DateFormat.Field` | `AM_PM` Constant identifying the time of day indicator (e.g.
    `static DateFormat.Field` | `DAY_OF_MONTH` Constant identifying the day of month field.
    `static DateFormat.Field` | `DAY_OF_WEEK` Constant identifying the day of week field.
    `static DateFormat.Field` | `DAY_OF_WEEK_IN_MONTH` Constant identifying the day of week field.
    `static DateFormat.Field` | `DAY_OF_YEAR` Constant identifying the day of year field.
    `static DateFormat.Field` | `ERA` Constant identifying the era field.
    `static DateFormat.Field` | `HOUR_OF_DAY0` Constant identifying the hour of day field, where the legal values are 0 to 23.
    `static DateFormat.Field` | `HOUR_OF_DAY1` Constant identifying the hour of day field, where the legal values are 1 to 24.
    `static DateFormat.Field` | `HOUR0` Constant identifying the hour field, where the legal values are 0 to 11.
    `static DateFormat.Field` | `HOUR1` Constant identifying the hour field, where the legal values are 1 to 12.
    `static DateFormat.Field` | `MILLISECOND` Constant identifying the millisecond field.
    `static DateFormat.Field` | `MINUTE` Constant identifying the minute field.
    `static DateFormat.Field` | `MONTH` Constant identifying the month field.
    `static DateFormat.Field` | `SECOND` Constant identifying the second field.
    `static DateFormat.Field` | `TIME_ZONE` Constant identifying the time zone field.
    `static DateFormat.Field` | `WEEK_OF_MONTH` Constant identifying the week of month field.
    `static DateFormat.Field` | `WEEK_OF_YEAR` Constant identifying the week of year field.
    `static DateFormat.Field` | `YEAR` Constant identifying the year field.

    - ### Fields inherited from class java.text.AttributedCharacterIterator.Attribute

      `INPUT_METHOD_SEGMENT, LANGUAGE, READING`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `Field(String name, int calendarField)` Creates a `Field`.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `int` | `getCalendarField()` Returns the `Calendar` field associated with this attribute.
    `static DateFormat.Field` | `ofCalendarField(int calendarField)` Returns the `Field` constant that corresponds to the `Calendar` constant `calendarField`.
    `protected Object` | `readResolve()` Resolves instances being deserialized to the predefined constants.

    - ### Methods inherited from class java.text.AttributedCharacterIterator.Attribute

      `equals, getName, hashCode, toString`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### ERA

          public static final DateFormat.Field ERA

      Constant identifying the era field.

    - #### YEAR

          public static final DateFormat.Field YEAR

      Constant identifying the year field.

    - #### MONTH

          public static final DateFormat.Field MONTH

      Constant identifying the month field.

    - #### DAY_OF_MONTH

          public static final DateFormat.Field DAY_OF_MONTH

      Constant identifying the day of month field.

    - #### HOUR_OF_DAY1

          public static final DateFormat.Field HOUR_OF_DAY1

      Constant identifying the hour of day field, where the legal values are 1 to 24.

    - #### HOUR_OF_DAY0

          public static final DateFormat.Field HOUR_OF_DAY0

      Constant identifying the hour of day field, where the legal values are 0 to 23.

    - #### MINUTE

          public static final DateFormat.Field MINUTE

      Constant identifying the minute field.

    - #### SECOND

          public static final DateFormat.Field SECOND

      Constant identifying the second field.

    - #### MILLISECOND

          public static final DateFormat.Field MILLISECOND

      Constant identifying the millisecond field.

    - #### DAY_OF_WEEK

          public static final DateFormat.Field DAY_OF_WEEK

      Constant identifying the day of week field.

    - #### DAY_OF_YEAR

          public static final DateFormat.Field DAY_OF_YEAR

      Constant identifying the day of year field.

    - #### DAY_OF_WEEK_IN_MONTH

          public static final DateFormat.Field DAY_OF_WEEK_IN_MONTH

      Constant identifying the day of week field.

    - #### WEEK_OF_YEAR

          public static final DateFormat.Field WEEK_OF_YEAR

      Constant identifying the week of year field.

    - #### WEEK_OF_MONTH

          public static final DateFormat.Field WEEK_OF_MONTH

      Constant identifying the week of month field.

    - #### AM_PM

          public static final DateFormat.Field AM_PM

      Constant identifying the time of day indicator (e.g. "a.m." or "p.m.") field.

    - #### HOUR1

          public static final DateFormat.Field HOUR1

      Constant identifying the hour field, where the legal values are 1 to 12.

    - #### HOUR0

          public static final DateFormat.Field HOUR0

      Constant identifying the hour field, where the legal values are 0 to 11.

    - #### TIME_ZONE

          public static final DateFormat.Field TIME_ZONE

      Constant identifying the time zone field.

  - ### Constructor Detail

    - #### Field

          protected Field(String name,
                          int calendarField)

      Creates a `Field`.
      Parameters:
        `name` - the name of the `Field`
        `calendarField` - the `Calendar` constant this `Field` corresponds to; any value, even one outside the range of legal `Calendar` values may be used, but `-1` should be used for values that don't correspond to legal `Calendar` values

  - ### Method Detail

    - #### ofCalendarField

          public static DateFormat.Field ofCalendarField(int calendarField)

      Returns the `Field` constant that corresponds to the `Calendar` constant `calendarField`. If there is no direct mapping between the `Calendar` constant and a `Field`, null is returned.
      Parameters:
        `calendarField` - Calendar field constant
      Returns:
        Field instance representing calendarField.
      Throws:
        `IllegalArgumentException` - if `calendarField` is not the value of a `Calendar` field constant.
      See Also:
        `Calendar`

    - #### getCalendarField

          public int getCalendarField()

      Returns the `Calendar` field associated with this attribute. For example, if this represents the hours field of a `Calendar`, this would return `Calendar.HOUR`. If there is no corresponding `Calendar` constant, this will return -1.
      Returns:
        Calendar constant for this field
      See Also:
        `Calendar`

    - #### readResolve

          protected Object readResolve()
                                throws InvalidObjectException

      Resolves instances being deserialized to the predefined constants.
      Overrides:
        `readResolve` in class `AttributedCharacterIterator.Attribute`
      Returns:
        resolved DateFormat.Field constant
      Throws:
        `InvalidObjectException` - if the constant could not be resolved.

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