ZoneOffsetTransitionRule (Java SE 23 & JDK 23)
Description: declaration: module: java.base, package: java.time.zone, class: ZoneOffsetTransitionRule
Keywords: java.time.zone.ZoneOffsetTransitionRule class

# Class ZoneOffsetTransitionRule

java.lang.Object
java.time.zone.ZoneOffsetTransitionRule

All Implemented Interfaces:
  `Serializable`

public final class ZoneOffsetTransitionRule extends Object implements Serializable
A rule expressing how to create a transition.

This class allows rules for identifying future transitions to be expressed. A rule might be written in many forms:

- the 16th March
- the Sunday on or after the 16th March
- the Sunday on or before the 16th March
- the last Sunday in February

These different rule types can be expressed and queried.

Implementation Requirements:
  This class is immutable and thread-safe.
Since:
  1.8
See Also:
  - Serialized Form

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static enum`
  `ZoneOffsetTransitionRule.TimeDefinition`
  A definition of the way a local time can be converted to the actual transition date-time.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `ZoneOffsetTransition`
  `createTransition(int year)`
  Creates a transition instance for the specified year.
  `boolean`
  `equals(Object otherRule)`
  Checks if this object equals another.
  `int`
  `getDayOfMonthIndicator()`
  Gets the indicator of the day-of-month of the transition.
  `DayOfWeek`
  `getDayOfWeek()`
  Gets the day-of-week of the transition.
  `LocalTime`
  `getLocalTime()`
  Gets the local time of day of the transition which must be checked with `isMidnightEndOfDay()`.
  `Month`
  `getMonth()`
  Gets the month of the transition.
  `ZoneOffset`
  `getOffsetAfter()`
  Gets the offset after the transition.
  `ZoneOffset`
  `getOffsetBefore()`
  Gets the offset before the transition.
  `ZoneOffset`
  `getStandardOffset()`
  Gets the standard offset in force at the transition.
  `ZoneOffsetTransitionRule.TimeDefinition`
  `getTimeDefinition()`
  Gets the time definition, specifying how to convert the time to an instant.
  `int`
  `hashCode()`
  Returns a suitable hash code.
  `boolean`
  `isMidnightEndOfDay()`
  Is the transition local time midnight at the end of day.
  `static ZoneOffsetTransitionRule`
  `of(Month month, int dayOfMonthIndicator, DayOfWeek dayOfWeek, LocalTime time, boolean timeEndOfDay, ZoneOffsetTransitionRule.TimeDefinition timeDefinition, ZoneOffset standardOffset, ZoneOffset offsetBefore, ZoneOffset offsetAfter)`
  Obtains an instance defining the yearly rule to create transitions between two offsets.
  `String`
  `toString()`
  Returns a string describing this object.

  ### Methods declared in class java.lang.Object

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

- ## Method Details

  - ### of

    public static ZoneOffsetTransitionRule of(Month month, int dayOfMonthIndicator, DayOfWeek dayOfWeek, LocalTime time, boolean timeEndOfDay, ZoneOffsetTransitionRule.TimeDefinition timeDefinition, ZoneOffset standardOffset, ZoneOffset offsetBefore, ZoneOffset offsetAfter)
    Obtains an instance defining the yearly rule to create transitions between two offsets.

    Applications should normally obtain an instance from `ZoneRules`. This factory is only intended for use when creating `ZoneRules`.

    Parameters:
      `month` - the month of the month-day of the first day of the cutover week, not null
      `dayOfMonthIndicator` - the day of the month-day of the cutover week, positive if the week is that day or later, negative if the week is that day or earlier, counting from the last day of the month, from -28 to 31 excluding 0
      `dayOfWeek` - the required day-of-week, null if the month-day should not be changed
      `time` - the cutover time in the 'before' offset, not null
      `timeEndOfDay` - whether the time is midnight at the end of day
      `timeDefinition` - how to interpret the cutover
      `standardOffset` - the standard offset in force at the cutover, not null
      `offsetBefore` - the offset before the cutover, not null
      `offsetAfter` - the offset after the cutover, not null
    Returns:
      the rule, not null
    Throws:
      `IllegalArgumentException` - if the day of month indicator is invalid
      `IllegalArgumentException` - if the end of day flag is true when the time is not midnight
      `IllegalArgumentException` - if `time.getNano()` returns non-zero value

  - ### getMonth

    public Month getMonth()
    Gets the month of the transition.

    If the rule defines an exact date then the month is the month of that date.

    If the rule defines a week where the transition might occur, then the month if the month of either the earliest or latest possible date of the cutover.

    Returns:
      the month of the transition, not null

  - ### getDayOfMonthIndicator

    public int getDayOfMonthIndicator()
    Gets the indicator of the day-of-month of the transition.

    If the rule defines an exact date then the day is the month of that date.

    If the rule defines a week where the transition might occur, then the day defines either the start of the end of the transition week.

    If the value is positive, then it represents a normal day-of-month, and is the earliest possible date that the transition can be. The date may refer to 29th February which should be treated as 1st March in non-leap years.

    If the value is negative, then it represents the number of days back from the end of the month where `-1` is the last day of the month. In this case, the day identified is the latest possible date that the transition can be.

    Returns:
      the day-of-month indicator, from -28 to 31 excluding 0

  - ### getDayOfWeek

    public DayOfWeek getDayOfWeek()
    Gets the day-of-week of the transition.

    If the rule defines an exact date then this returns null.

    If the rule defines a week where the cutover might occur, then this method returns the day-of-week that the month-day will be adjusted to. If the day is positive then the adjustment is later. If the day is negative then the adjustment is earlier.

    Returns:
      the day-of-week that the transition occurs, null if the rule defines an exact date

  - ### getLocalTime

    public LocalTime getLocalTime()
    Gets the local time of day of the transition which must be checked with `isMidnightEndOfDay()`.

    The time is converted into an instant using the time definition.

    Returns:
      the local time of day of the transition, not null

  - ### isMidnightEndOfDay

    public boolean isMidnightEndOfDay()
    Is the transition local time midnight at the end of day.

    The transition may be represented as occurring at 24:00.

    Returns:
      whether a local time of midnight is at the start or end of the day

  - ### getTimeDefinition

    public ZoneOffsetTransitionRule.TimeDefinition getTimeDefinition()
    Gets the time definition, specifying how to convert the time to an instant.

    The local time can be converted to an instant using the standard offset, the wall offset or UTC.

    Returns:
      the time definition, not null

  - ### getStandardOffset

    public ZoneOffset getStandardOffset()
    Gets the standard offset in force at the transition.
    Returns:
      the standard offset, not null

  - ### getOffsetBefore

    public ZoneOffset getOffsetBefore()
    Gets the offset before the transition.
    Returns:
      the offset before, not null

  - ### getOffsetAfter

    public ZoneOffset getOffsetAfter()
    Gets the offset after the transition.
    Returns:
      the offset after, not null

  - ### createTransition

    public ZoneOffsetTransition createTransition(int year)
    Creates a transition instance for the specified year.

    Calculations are performed using the ISO-8601 chronology.

    Parameters:
      `year` - the year to create a transition for, not null
    Returns:
      the transition instance, not null

  - ### equals

    public boolean equals(Object otherRule)
    Checks if this object equals another.

    The entire state of the object is compared.

    Overrides:
      `equals` in class `Object`
    Parameters:
      `otherRule` - the other object to compare to, null returns false
    Returns:
      true if equal
    See Also:
      - `Object.hashCode()`
      - `HashMap`

  - ### hashCode

    public int hashCode()
    Returns a suitable hash code.
    Overrides:
      `hashCode` in class `Object`
    Returns:
      the hash code
    See Also:
      - `Object.equals(java.lang.Object)`
      - `System.identityHashCode(java.lang.Object)`

  - ### toString

    public String toString()
    Returns a string describing this object.
    Overrides:
      `toString` in class `Object`
    Returns:
      a string for debugging, not null