Added in API level 1

Summary: Constants | Ctors | Methods | Inherited Methods

TimeZone

public abstract class TimeZone
extends Object implements Serializable, Cloneable

java.lang.Object
↳	java.util.TimeZone

Known direct subclasses

SimpleTimeZone

SimpleTimeZone SimpleTimeZone is a concrete subclass of TimeZone that represents a time zone for use with a Gregorian calendar.

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:

 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
         GMT Sign Hours Minutes
         GMT Sign Hours
 Sign: one of
         + -
 Hours:
         Digit
         Digit Digit
 Minutes:
         Digit Digit
 Digit: one of
         0 1 2 3 4 5 6 7 8 9

Hours must be between 0 to 23 and Minutes 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
 Sign: one of
         + -
 TwoDigitHours:
         Digit Digit
 Minutes:
         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".

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.

See also:

Summary

Constants
`int`	`LONG` A style specifier for `getDisplayName()` indicating a long name, such as "Pacific Standard Time."
`int`	`SHORT` A style specifier for `getDisplayName()` indicating a short name, such as "PST."

Public constructors
`TimeZone()` Sole constructor.

Public methods
`Object`	`clone()` Creates a copy of this `TimeZone`.
`static String[]`	`getAvailableIDs()` Gets all the available IDs supported.
`static String[]`	`getAvailableIDs(int rawOffset)` Gets the available IDs according to the given time zone offset in milliseconds.
`int`	`getDSTSavings()` Returns the amount of time to be added to local standard time to get local wall clock time.
`static TimeZone`	`getDefault()` Gets the default `TimeZone` for this host.
`String`	`getDisplayName(boolean daylightTime, int style, Locale locale)` Returns the `short` or `long` name of this time zone with either standard or daylight time, as written in `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`.
`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.
`final String`	`getDisplayName()` Returns a long standard time name of this `TimeZone` suitable for presentation to the user in the default locale.
`String`	`getID()` Gets the ID of this time zone.
`int`	`getOffset(long date)` Returns the offset of this time zone from UTC at the specified date.
`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.
`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 timeZone)` 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.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the 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(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.
`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()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

LONG

Added in API level 1

public static final int LONG

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

See also:

SHORT

Constant Value: 1 (0x00000001)

SHORT

Added in API level 1

public static final int SHORT

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

See also:

LONG

Constant Value: 0 (0x00000000)

Public constructors

TimeZone

Added in API level 1

public TimeZone ()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Public methods

clone

Added in API level 1

public Object clone ()

Creates a copy of this TimeZone.

Returns
`Object`	a clone of this `TimeZone`

getAvailableIDs

Added in API level 1

public static String[] getAvailableIDs ()

Gets all the available IDs supported.

Returns
`String[]`	an array of IDs.

getAvailableIDs

Added in API level 1

public static String[] getAvailableIDs (int rawOffset)

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

Parameters
`rawOffset`	`int`: the given time zone GMT offset in milliseconds.

Returns
`String[]`	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()

getDSTSavings

Added in API level 1

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
`int`	the amount of saving time in milliseconds

See also:

getDefault

Added in API level 1

public static TimeZone getDefault ()

Gets the default TimeZone for this host. The source of the default TimeZone may vary with implementation.

Returns
`TimeZone`	a default `TimeZone`.

See also:

setDefault(TimeZone)

getDisplayName

Added in API level 1

public String getDisplayName (boolean daylightTime, 
                int style, 
                Locale locale)

Returns the short or long name of this time zone with either standard or daylight time, as written in locale. If the name is not available, the result is in the format GMT[+-]hh:mm.

Parameters
`daylightTime`	`boolean`: true for daylight time, false for standard time.
`style`	`int`: either `TimeZone#LONG` or `TimeZone#SHORT`.
`locale`	`Locale`: the display locale.

Returns
`String`

getDisplayName

Added in API level 1

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:

 getDisplayName(false, LONG, locale)

Parameters
`locale`	`Locale`: the locale in which to supply the display name.

Returns
`String`	the human-readable name of this time zone in the given locale.

Throws
`NullPointerException`	if `locale` is `null`.

See also:

getDisplayName(boolean, int, Locale)

getDisplayName

Added in API level 1

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:

 getDisplayName(daylight, style,
                Locale.getDefault(Locale.Category#DISPLAY))

Parameters
`daylight`	`boolean`: `true` specifying a Daylight Saving Time name, or `false` specifying a Standard Time name
`style`	`int`: either `LONG` or `SHORT`

Returns
`String`	the human-readable name of this time zone in the default locale.

Throws
`IllegalArgumentException`	if `style` is invalid.

See also:

getDisplayName

Added in API level 1

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:

 getDisplayName(false, LONG,
                Locale.getDefault(Locale.Category#DISPLAY))

Returns
`String`	the human-readable name of this time zone in the default locale.

See also:

getID

Added in API level 1

public String getID ()

Gets the ID of this time zone.

Returns
`String`	the ID of this time zone.

getOffset

Added in API level 1

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`	`long`: the date represented in milliseconds since January 1, 1970 00:00:00 GMT

Returns
`int`	the amount of time in milliseconds to add to UTC to get local time.

See also:

getOffset

Added in API level 1

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`	`int`: the era of the given date.
`year`	`int`: the year in the given date.
`month`	`int`: the month in the given date. Month is 0-based. e.g., 0 for January.
`day`	`int`: the day-in-month of the given date.
`dayOfWeek`	`int`: the day-of-week of the given date.
`milliseconds`	`int`: the milliseconds in day in standard local time.

Returns
`int`	the offset in milliseconds to add to GMT to get local time.

See also:

getRawOffset

Added in API level 1

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
`int`	the amount of raw offset time in milliseconds to add to UTC.

See also:

Calendar.ZONE_OFFSET

getTimeZone

Added in API level 1

public static TimeZone getTimeZone (String id)

Gets the TimeZone for the given ID.

Parameters
`id`	`String`: 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
`TimeZone`	the specified `TimeZone`, or the GMT zone if the given ID cannot be understood.

getTimeZone

Added in API level 26

public static TimeZone getTimeZone (ZoneId zoneId)

Gets the TimeZone for the given zoneId.

Parameters
`zoneId`	`ZoneId`: a `ZoneId` from which the time zone ID is obtained

Returns
`TimeZone`	the specified `TimeZone`, or the GMT zone if the given ID cannot be understood.

Throws
`NullPointerException`	if `zoneId` is `null`

hasSameRules

Added in API level 1

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`	`TimeZone`: the `TimeZone` object to be compared with

Returns
`boolean`	true if the other zone is not null and is the same as this one, with the possible exception of the ID

inDaylightTime

Added in API level 1

public abstract boolean inDaylightTime (Date date)

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

Parameters
`date`	`Date`: the given Date.

Returns
`boolean`	`true` if the given date is in Daylight Saving Time, `false`, otherwise.

observesDaylightTime

Added in API level 24

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
`boolean`	`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.

See also:

setDefault

Added in API level 1

public static void setDefault (TimeZone timeZone)

Sets the TimeZone that is returned by the getDefault method. timeZone is cached. If timeZone is null, the cached default TimeZone is cleared. This method doesn't change the value of the user.timezone property.

Parameters
`timeZone`	`TimeZone`: the new default `TimeZone`, or null

See also:

getDefault()

setID

Added in API level 1

public void setID (String ID)

Sets the time zone ID. This does not change any other data in the time zone object.

Parameters
`ID`	`String`: the new time zone ID.

setRawOffset

Added in API level 1

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`	`int`: the given base time zone offset to GMT.

toZoneId

Added in API level 26

public ZoneId toZoneId ()

Converts this TimeZone object to a ZoneId.

Returns
`ZoneId`	a `ZoneId` representing the same time zone as this `TimeZone`

useDaylightTime

Added in API level 1

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
`boolean`	`true` if this `TimeZone` uses Daylight Saving Time, `false`, otherwise.

See also: