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import {ZoneOffsetTransition} from 'js-joda/src/zone/ZoneOffsetTransition.js'
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ZoneOffsetTransition

A transition between two offsets caused by a discontinuity in the local time-line.

A transition between two offsets is normally the result of a daylight savings cutover. The discontinuity is normally a gap in spring and an overlap in autumn. ZoneOffsetTransition models the transition between the two offsets.

Gaps occur where there are local date-times that simply do not not exist. An example would be when the offset changes from +03:00 to +04:00. This might be described as 'the clocks will move forward one hour tonight at 1am'.

Overlaps occur where there are local date-times that exist twice. An example would be when the offset changes from +04:00 to +03:00. This might be described as 'the clocks will move back one hour tonight at 2am'.

Static Method Summary

Static Public Methods
public static

of(transition: LocalDateTime, offsetBefore: ZoneOffset, offsetAfter: ZoneOffset): ZoneOffsetTransition

Obtains an instance defining a transition between two offsets.

Method Summary

Public Methods
public

Compares this transition to another based on the transition instant.

public

Gets the local transition date-time, as would be expressed with the 'after' offset.

public

Gets the local transition date-time, as would be expressed with the 'before' offset.

public

Gets the duration of the transition.

public

Gets the duration of the transition in seconds.

public

equals(other: *): *

Checks if this object equals another.

public

Returns a suitable hash code.

public

Gets the transition instant.

public

Does this transition represent a gap in the local time-line.

public

Does this transition represent a gap in the local time-line.

public

Checks if the specified offset is valid during this transition.

public

Gets the offset after the transition.

public

Gets the offset before the transition.

public

Gets the transition instant as an epoch second.

public

Returns a string describing this object.

public

Gets the valid offsets during this transition.

Static Public Methods

public static of(transition: LocalDateTime, offsetBefore: ZoneOffset, offsetAfter: ZoneOffset): ZoneOffsetTransition source

Obtains an instance defining a transition between two offsets.

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

Params:

NameTypeAttributeDescription
transition LocalDateTime

the transition date-time at the transition, which never actually occurs, expressed local to the before offset, not null

offsetBefore ZoneOffset

the offset before the transition, not null

offsetAfter ZoneOffset

the offset at and after the transition, not null

Return:

ZoneOffsetTransition

the transition, not null

Throw:

*

IllegalArgumentException if offsetBefore and offsetAfter are equal, or transition.getNano returns non-zero value

Public Methods

public compareTo(transition: ZoneOffsetTransition): number source

Compares this transition to another based on the transition instant.

This compares the instants of each transition. The offsets are ignored, making this order inconsistent with equals.

Params:

NameTypeAttributeDescription
transition ZoneOffsetTransition

the transition to compare to, not null

Return:

number

the comparator value, negative if less, positive if greater

public dateTimeAfter(): LocalDateTime source

Gets the local transition date-time, as would be expressed with the 'after' offset.

This is the first date-time after the discontinuity, when the new offset applies.

The combination of the 'before' date-time and offset represents the same instant as the 'after' date-time and offset.

Return:

LocalDateTime

the transition date-time expressed with the after offset, not null

public dateTimeBefore(): LocalDateTime source

Gets the local transition date-time, as would be expressed with the 'before' offset.

This is the date-time where the discontinuity begins expressed with the 'before' offset. At this instant, the 'after' offset is actually used, therefore the combination of this date-time and the 'before' offset will never occur.

The combination of the 'before' date-time and offset represents the same instant as the 'after' date-time and offset.

Return:

LocalDateTime

the transition date-time expressed with the before offset, not null

public duration(): Duration source

Gets the duration of the transition.

In most cases, the transition duration is one hour, however this is not always the case. The duration will be positive for a gap and negative for an overlap. Time-zones are second-based, so the nanosecond part of the duration will be zero.

Return:

Duration

the duration of the transition, positive for gaps, negative for overlaps

public durationSeconds(): number source

Gets the duration of the transition in seconds.

Return:

number

the duration in seconds

public equals(other: *): * source

Checks if this object equals another.

The entire state of the object is compared.

Params:

NameTypeAttributeDescription
other *

the other object to compare to, null returns false

Return:

*

true if equal

public hashCode(): number source

Returns a suitable hash code.

Return:

number

the hash code

public instant(): Instant source

Gets the transition instant.

This is the instant of the discontinuity, which is defined as the first instant that the 'after' offset applies.

The methods getInstant, getDateTimeBefore and getDateTimeAfter all represent the same instant.

Return:

Instant

the transition instant, not null

public isGap(): boolean source

Does this transition represent a gap in the local time-line.

Gaps occur where there are local date-times that simply do not not exist. An example would be when the offset changes from +01:00 to +02:00. This might be described as 'the clocks will move forward one hour tonight at 1am'.

Return:

boolean

true if this transition is a gap, false if it is an overlap

public isOverlap(): boolean source

Does this transition represent a gap in the local time-line.

Overlaps occur where there are local date-times that exist twice. An example would be when the offset changes from +02:00 to +01:00. This might be described as 'the clocks will move back one hour tonight at 2am'.

Return:

boolean

true if this transition is an overlap, false if it is a gap

public isValidOffset(offset: ZoneOffset): boolean source

Checks if the specified offset is valid during this transition.

This checks to see if the given offset will be valid at some point in the transition. A gap will always return false. An overlap will return true if the offset is either the before or after offset.

Params:

NameTypeAttributeDescription
offset ZoneOffset

the offset to check, null returns false

Return:

boolean

true if the offset is valid during the transition

public offsetAfter(): ZoneOffset source

Gets the offset after the transition.

This is the offset in use on and after the instant of the transition.

Return:

ZoneOffset

the offset after the transition, not null

public offsetBefore(): ZoneOffset source

Gets the offset before the transition.

This is the offset in use before the instant of the transition.

Return:

ZoneOffset

the offset before the transition, not null

public toEpochSecond(): number source

Gets the transition instant as an epoch second.

Return:

number

the transition epoch second

public toString(): string source

Returns a string describing this object.

Return:

string

a string for debugging, not null

public validOffsets(): ZoneOffset[] source

Gets the valid offsets during this transition.

A gap will return an empty list, while an overlap will return both offsets.

Return:

ZoneOffset[]

the list of valid offsets