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TimeZone (Java SE 26 & JDK 26)

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java.lang.Object

java.util.TimeZone

All Implemented Interfaces: Serializable, Cloneable Direct Known Subclasses: SimpleTimeZone

public abstract class TimeZone extends Object implements Serializable, Cloneable

TimeZone represents a time zone offset, and also figures out daylight savings.

Typically, you get a TimeZone using getDefault which creates a TimeZone based on the time zone where the program is running. For example, for a program running in Japan, getDefault creates a TimeZone object based on Japanese Standard Time.

You can also get a TimeZone using getTimeZone along with a time zone ID. For instance, the time zone ID for the U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a U.S. Pacific Time TimeZone object with:

Copy TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");

You can use the getAvailableIDs method to iterate through all the supported time zone IDs. You can then choose a supported ID to get a TimeZone. If the time zone you want is not represented by one of the supported IDs, then a custom time zone ID can be specified to produce a TimeZone. The syntax of a custom time zone ID is: CustomID: GMT Sign Hours : Minutes : Seconds GMT Sign Hours : Minutes GMT Sign Hours Minutes GMT Sign Hours Sign: one of + - Hours: Digit Digit Digit Minutes: Digit Digit Seconds: Digit Digit Digit: one of 0 1 2 3 4 5 6 7 8 9 Hours must be between 0 to 23 and Minutes/Seconds must be between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten hours and ten minutes ahead of GMT, respectively.

The format is locale independent and digits must be taken from the Basic Latin block of the Unicode standard. No daylight saving time transition schedule can be specified with a custom time zone ID. If the specified string doesn't match the syntax, "GMT" is used.

When creating a TimeZone, the specified custom time zone ID is normalized in the following syntax: NormalizedCustomID: GMT Sign TwoDigitHours : Minutes [ColonSeconds] Sign: one of + - TwoDigitHours: Digit Digit Minutes: Digit Digit ColonSeconds: : Digit Digit Digit: one of 0 1 2 3 4 5 6 7 8 9 For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00". ColonSeconds part only appears if the seconds value is non-zero.

Three-letter time zone IDs

For compatibility with JDK 1.1.x, some other three-letter time zone IDs (such as "PST", "CTT", "AST") are also supported. However, their use is deprecated because the same abbreviation is often used for multiple time zones (for example, "CST" could be U.S. "Central Standard Time" and "China Standard Time"), and the Java platform can then only recognize one of them. The full list of deprecated three-letter time zone IDs and their mappings can be viewed at ZoneId.SHORT_IDS.

Since: 1.1 See Also:

Field Summary

Fields

Modifier and Type

Field

Description

static final int

LONG

A style specifier for getDisplayName() indicating a long name, such as "Pacific Standard Time."

static final int

SHORT

A style specifier for getDisplayName() indicating a short name, such as "PST."
Constructor Summary

Constructors

Constructor

Description

TimeZone()

Sole constructor.
Method Summary

All MethodsStatic MethodsInstance MethodsAbstract MethodsConcrete Methods

Modifier and Type

Method

Description

static Stream<String>

availableIDs()

Returns a stream of the available IDs supported.

static Stream<String>

availableIDs(int rawOffset)

Gets the available IDs according to the given time zone offset in milliseconds.

Object

clone()

Creates a copy of this TimeZone.

static String[]

getAvailableIDs()

Returns an array of the available IDs supported.

static String[]

getAvailableIDs(int rawOffset)

Gets the available IDs according to the given time zone offset in milliseconds.

static TimeZone

getDefault()

Gets the default TimeZone of the Java virtual machine.

final String

getDisplayName()

Returns a long standard time name of this TimeZone suitable for presentation to the user in the default locale.

final String

getDisplayName(boolean daylight, int style)

Returns a name in the specified style of this TimeZone suitable for presentation to the user in the default locale.

String

getDisplayName(boolean daylight, int style, Locale locale)

Returns a name in the specified style of this TimeZone suitable for presentation to the user in the specified locale.

final String

getDisplayName(Locale locale)

Returns a long standard time name of this TimeZone suitable for presentation to the user in the specified locale.

int

getDSTSavings()

Returns the amount of time to be added to local standard time to get local wall clock time.

String

getID()

Gets the ID of this time zone.

abstract int

getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds)

Gets the time zone offset, for current date, modified in case of daylight savings.

int

getOffset(long date)

Returns the offset of this time zone from UTC at the specified date.

abstract int

getRawOffset()

Returns the amount of time in milliseconds to add to UTC to get standard time in this time zone.

static TimeZone

getTimeZone(String ID)

Gets the TimeZone for the given ID.

static TimeZone

getTimeZone(ZoneId zoneId)

Gets the TimeZone for the given zoneId.

boolean

hasSameRules(TimeZone other)

Returns true if this zone has the same rule and offset as another zone.

abstract boolean

inDaylightTime(Date date)

Queries if the given date is in Daylight Saving Time in this time zone.

boolean

observesDaylightTime()

Returns true if this TimeZone is currently in Daylight Saving Time, or if a transition from Standard Time to Daylight Saving Time occurs at any future time.

static void

setDefault(TimeZone zone)

Sets the TimeZone that is returned by the getDefault method.

void

setID(String ID)

Sets the time zone ID.

abstract void

setRawOffset(int offsetMillis)

Sets the base time zone offset to GMT.

ZoneId

toZoneId()

Converts this TimeZone object to a ZoneId.

abstract boolean

useDaylightTime()

Queries if this TimeZone uses Daylight Saving Time.

Methods declared in class Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type

Method

Description

boolean

equals(Object obj)

Indicates whether some other object is "equal to" this one.

protected void

finalize()

Deprecated, for removal: This API element is subject to removal in a future version.
Finalization is deprecated and subject to removal in a future release.

final Class<?>

getClass()

Returns the runtime class of this Object.

int

hashCode()

Returns a hash code value for this object.

final void

notify()

Wakes up a single thread that is waiting on this object's monitor.

final void

notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String

toString()

Returns a string representation of the object.

final void

wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

final void

wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void

wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details
- SHORT
  public static final int SHORT
  
  A style specifier for getDisplayName() indicating a short name, such as "PST."
  Since: 1.2 See Also:
  - LONG
  - Constant Field Values
- LONG
  public static final int LONG
  
  A style specifier for getDisplayName() indicating a long name, such as "Pacific Standard Time."
  Since: 1.2 See Also:
  - SHORT
  - Constant Field Values
Constructor Details
- TimeZone
  
  public TimeZone()
  
  Sole constructor. (For invocation by subclass constructors, typically implicit.)
Method Details
- getOffset
  public abstract int getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds)
  
  Gets the time zone offset, for current date, modified in case of daylight savings. This is the offset to add to UTC to get local time.
  This method returns a historically correct offset if an underlying TimeZone implementation subclass supports historical Daylight Saving Time schedule and GMT offset changes.
  Parameters: era - the era of the given date. year - the year in the given date. month - the month in the given date. Month is 0-based. e.g., 0 for January. day - the day-in-month of the given date. dayOfWeek - the day-of-week of the given date. milliseconds - the milliseconds in day in standard local time. Returns: the offset in milliseconds to add to GMT to get local time. See Also:
  - Calendar.ZONE_OFFSET
  - Calendar.DST_OFFSET
- getOffset
  public int getOffset(long date)
  
  Returns the offset of this time zone from UTC at the specified date. If Daylight Saving Time is in effect at the specified date, the offset value is adjusted with the amount of daylight saving.
  This method returns a historically correct offset value if an underlying TimeZone implementation subclass supports historical Daylight Saving Time schedule and GMT offset changes.
  Parameters: date - the date represented in milliseconds since January 1, 1970 00:00:00 GMT Returns: the amount of time in milliseconds to add to UTC to get local time. Since: 1.4 See Also:
  - Calendar.ZONE_OFFSET
  - Calendar.DST_OFFSET
- setRawOffset
  
  public abstract void setRawOffset(int offsetMillis)
  
  Sets the base time zone offset to GMT. This is the offset to add to UTC to get local time.
  If an underlying TimeZone implementation subclass supports historical GMT offset changes, the specified GMT offset is set as the latest GMT offset and the difference from the known latest GMT offset value is used to adjust all historical GMT offset values.
  Parameters: offsetMillis - the given base time zone offset to GMT.
- getRawOffset
  public abstract int getRawOffset()
  
  Returns the amount of time in milliseconds to add to UTC to get standard time in this time zone. Because this value is not affected by daylight saving time, it is called raw offset.
  If an underlying TimeZone implementation subclass supports historical GMT offset changes, the method returns the raw offset value of the current date. In Honolulu, for example, its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and this method always returns -36000000 milliseconds (i.e., -10 hours).
  Returns: the amount of raw offset time in milliseconds to add to UTC. See Also:
  - Calendar.ZONE_OFFSET
- getID
  
  public String getID()
  
  Gets the ID of this time zone.
  Returns: the ID of this time zone.
- setID
  
  public void setID(String ID)
  
  Sets the time zone ID. This does not change any other data in the time zone object.
  Implementation Requirements: The default implementation throws a NullPointerException if ID is null Parameters: ID - the new time zone ID. Throws: NullPointerException - This method may throw a NullPointerException if ID is null
- getDisplayName
  public final String getDisplayName()
  
  Returns a long standard time name of this TimeZone suitable for presentation to the user in the default locale.
  This method is equivalent to:
  Copy getDisplayName(false, LONG, Locale.getDefault(Locale.Category.DISPLAY));
  
  Returns: the human-readable name of this time zone in the default locale. Since: 1.2 See Also:
- getDisplayName
  public final String getDisplayName(Locale locale)
  
  Returns a long standard time name of this TimeZone suitable for presentation to the user in the specified locale.
  This method is equivalent to:
  Copy getDisplayName(false, LONG, locale);
  
  Parameters: locale - the locale in which to supply the display name. Returns: the human-readable name of this time zone in the given locale. Throws: NullPointerException - if locale is null. Since: 1.2 See Also:
  - getDisplayName(boolean, int, Locale)
- getDisplayName
  public final String getDisplayName(boolean daylight, int style)
  
  Returns a name in the specified style of this TimeZone suitable for presentation to the user in the default locale. If the specified daylight is true, a Daylight Saving Time name is returned (even if this TimeZone doesn't observe Daylight Saving Time). Otherwise, a Standard Time name is returned.
  This method is equivalent to:
  Copy getDisplayName(daylight, style, Locale.getDefault(Locale.Category.DISPLAY));
  
  Parameters: daylight - true specifying a Daylight Saving Time name, or false specifying a Standard Time name style - either LONG or SHORT Returns: the human-readable name of this time zone in the default locale. Throws: IllegalArgumentException - if style is invalid. Since: 1.2 See Also:
- getDisplayName
  public String getDisplayName(boolean daylight, int style, Locale locale)
  
  Returns a name in the specified style of this TimeZone suitable for presentation to the user in the specified locale. If the specified daylight is true, a Daylight Saving Time name is returned (even if this TimeZone doesn't observe Daylight Saving Time). Otherwise, a Standard Time name is returned.
  When looking up a time zone name, the default Locale search path of ResourceBundle derived from the specified locale is used. (No fallback Locale search is performed.) If a time zone name in any Locale of the search path, including Locale.ROOT, is found, the name is returned. Otherwise, a string in the normalized custom ID format is returned.
  Implementation Requirements: The default implementation throws an IllegalArgumentException if style is invalid or a NullPointerException if ID is null. Parameters: daylight - true specifying a Daylight Saving Time name, or false specifying a Standard Time name style - either LONG or SHORT locale - the locale in which to supply the display name. Returns: the human-readable name of this time zone in the given locale. Throws: IllegalArgumentException - This method may throw an IllegalArgumentException if style is invalid. NullPointerException - This method may throw a NullPointerException if ID is null Since: 1.2 See Also:
  - DateFormatSymbols.getZoneStrings()
- getDSTSavings
  public int getDSTSavings()
  
  Returns the amount of time to be added to local standard time to get local wall clock time.
  The default implementation returns 3600000 milliseconds (i.e., one hour) if a call to useDaylightTime() returns true. Otherwise, 0 (zero) is returned.
  If an underlying TimeZone implementation subclass supports historical and future Daylight Saving Time schedule changes, this method returns the amount of saving time of the last known Daylight Saving Time rule that can be a future prediction.
  If the amount of saving time at any given time stamp is required, construct a Calendar with this TimeZone and the time stamp, and call Calendar.get(Calendar.DST_OFFSET).
  Returns: the amount of saving time in milliseconds Since: 1.4 See Also:
- useDaylightTime
  public abstract boolean useDaylightTime()
  
  Queries if this TimeZone uses Daylight Saving Time.
  If an underlying TimeZone implementation subclass supports historical and future Daylight Saving Time schedule changes, this method refers to the last known Daylight Saving Time rule that can be a future prediction and may not be the same as the current rule. Consider calling observesDaylightTime() if the current rule should also be taken into account.
  Returns: true if this TimeZone uses Daylight Saving Time, false, otherwise. See Also:
  - inDaylightTime(Date)
  - Calendar.DST_OFFSET
- observesDaylightTime
  public boolean observesDaylightTime()
  
  Returns true if this TimeZone is currently in Daylight Saving Time, or if a transition from Standard Time to Daylight Saving Time occurs at any future time.
  The default implementation returns true if useDaylightTime() or inDaylightTime(new Date()) returns true.
  Returns: true if this TimeZone is currently in Daylight Saving Time, or if a transition from Standard Time to Daylight Saving Time occurs at any future time; false otherwise. Since: 1.7 See Also:
- inDaylightTime
  
  public abstract boolean inDaylightTime(Date date)
  
  Queries if the given date is in Daylight Saving Time in this time zone.
  Parameters: date - the given Date. Returns: true if the given date is in Daylight Saving Time, false, otherwise. Throws: NullPointerException - This method may throw a NullPointerException if date is null
- getTimeZone
  
  public static TimeZone getTimeZone(String ID)
  
  Gets the TimeZone for the given ID.
  Parameters: ID - the ID for a TimeZone, either an abbreviation such as "PST", a full name such as "America/Los_Angeles", or a custom ID such as "GMT-8:00". Note that the support of abbreviations is for JDK 1.1.x compatibility only and full names should be used. Returns: the specified TimeZone, or the GMT zone if the given ID cannot be understood. Throws: NullPointerException - if ID is null
- getTimeZone
  
  public static TimeZone getTimeZone(ZoneId zoneId)
  
  Gets the TimeZone for the given zoneId.
  Parameters: zoneId - a ZoneId from which the time zone ID is obtained Returns: the specified TimeZone, or the GMT zone if the given ID cannot be understood. Throws: NullPointerException - if zoneId is null Since: 1.8
- toZoneId
  
  public ZoneId toZoneId()
  
  Converts this TimeZone object to a ZoneId.
  Returns: a ZoneId representing the same time zone as this TimeZone Since: 1.8
- getAvailableIDs
  public static String[] getAvailableIDs(int rawOffset)
  
  Gets the available IDs according to the given time zone offset in milliseconds.
  API Note: Consider using availableIDs(int) which returns a stream of the available time zone IDs according to the given offset. Parameters: rawOffset - the given time zone GMT offset in milliseconds. Returns: an array of IDs, where the time zone for that ID has the specified GMT offset. For example, "America/Phoenix" and "America/Denver" both have GMT-07:00, but differ in daylight saving behavior. See Also:
  - getRawOffset()
  - availableIDs(int)
- getAvailableIDs
  public static String[] getAvailableIDs()
  
  Returns an array of the available IDs supported.
  API Note: Consider using availableIDs() which returns a stream of the available time zone IDs. Returns: an array of the available IDs supported See Also:
  - availableIDs()
- availableIDs
  public static Stream<String> availableIDs(int rawOffset)
  
  Gets the available IDs according to the given time zone offset in milliseconds.
  Implementation Note: Unlike getAvailableIDs(int), this method does not create a copy of the TimeZone IDs array. Parameters: rawOffset - the given time zone GMT offset in milliseconds. Returns: a stream of IDs, where the time zone for that ID has the specified GMT offset. For example, "America/Phoenix" and "America/Denver" both have GMT-07:00, but differ in daylight saving behavior. Since: 25 See Also:
  - getRawOffset()
  - getAvailableIDs(int)
- availableIDs
  public static Stream<String> availableIDs()
  
  Returns a stream of the available IDs supported.
  Implementation Note: Unlike getAvailableIDs(), this method does not create a copy of the TimeZone IDs array. Returns: a stream of the available IDs supported Since: 25 See Also:
  - getAvailableIDs()
- getDefault
  public static TimeZone getDefault()
  Gets the default TimeZone of the Java virtual machine. If the cached default TimeZone is available, its clone is returned. Otherwise, the method takes the following steps to determine the default time zone.
  - Use the user.timezone property value as the default time zone ID if it's available.
  - Detect the platform time zone ID. The source of the platform time zone and ID mapping may vary with implementation.
  - Use GMT as the last resort if the given or detected time zone ID is unknown.
  The default TimeZone created from the ID is cached, and its clone is returned. The user.timezone property value is set to the ID upon return.
  Returns: the default TimeZone See Also:
  - setDefault(TimeZone)
- setDefault
  public static void setDefault(TimeZone zone)
  
  Sets the TimeZone that is returned by the getDefault method. zone is cached. If zone is null, the cached default TimeZone is cleared. This method doesn't change the value of the user.timezone property.
  Parameters: zone - the new default TimeZone, or null See Also:
  - getDefault()
- hasSameRules
  
  public boolean hasSameRules(TimeZone other)
  
  Returns true if this zone has the same rule and offset as another zone. That is, if this zone differs only in ID, if at all. Returns false if the other zone is null.
  Parameters: other - the TimeZone object to be compared with Returns: true if the other zone is not null and is the same as this one, with the possible exception of the ID Since: 1.2
- clone
  public Object clone()
  
  Creates a copy of this TimeZone.
  Overrides: clone in class Object Returns: a clone of this TimeZone See Also:
  - Cloneable

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Class TimeZone

Three-letter time zone IDs

Field Summary

Constructor Summary

Method Summary

Methods declared in class Object

Field Details

SHORT

LONG

Constructor Details

TimeZone

Method Details

getOffset

getOffset

setRawOffset

getRawOffset

getID

setID

getDisplayName

getDisplayName

getDisplayName

getDisplayName

getDSTSavings

useDaylightTime

observesDaylightTime

inDaylightTime

getTimeZone

getTimeZone

toZoneId

getAvailableIDs

getAvailableIDs

availableIDs

availableIDs

getDefault

setDefault

hasSameRules

clone