Class TimeZone

java.lang.Object
com.ibm.icu.util.TimeZone
All Implemented Interfaces:
Freezable<TimeZone>, Serializable, Cloneable
Direct Known Subclasses:
BasicTimeZone

public abstract class TimeZone extends Object implements Serializable, Cloneable, Freezable<TimeZone>
.

TimeZone represents a time zone offset, and also computes 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(String) 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, or getCanonicalID method to check if a time zone ID is supported or not. 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 you can create a custom time zone ID with the following syntax:
 GMT[+|-]hh[[:]mm]
 
For example, you might specify GMT+14:00 as a custom time zone ID. The TimeZone that is returned when you specify a custom time zone ID uses the specified offset from GMT(=UTC) and does not observe daylight saving time. For example, you might specify GMT+14:00 as a custom time zone ID to create a TimeZone representing 14 hours ahead of GMT (with no daylight saving time). In addition, getCanonicalID can also be used to normalize a custom time zone ID.

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.

Note: Starting from ICU4J 4.0, you can optionally choose JDK TimeZone as the time zone implementation. The TimeZone factory method getTimeZone creates an instance of ICU's own TimeZone subclass by default. If you want to use the JDK implementation always, you can set the default time zone implementation type by the new method setDefaultTimeZoneType. Alternatively, you can change the initial default implementation type by setting a property below.

 #
 # The default TimeZone implementation type used by the ICU TimeZone
 # factory method. [ ICU | JDK ]
 #
 com.ibm.icu.util.TimeZone.DefaultTimeZoneType = ICU
 

This property is included in ICUConfig.properties in com.ibm.icu package. When the TimeZone class is loaded, the initialization code checks if the property com.ibm.icu.util.TimeZone.DefaultTimeZoneType=xxx is defined by the system properties. If not available, then it loads ICUConfig.properties to get the default time zone implementation type. The property setting is only used for the initial default value and you can change the default type by calling setDefaultTimeZoneType at runtime.

Author:
Mark Davis, Deborah Goldsmith, Chen-Lieh Huang, Alan Liu
See Also:
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    System time zone type constants used by filtering zones in getAvailableIDs(SystemTimeZoneType, String, Integer)
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    A style specifier for getDisplayName() indicating a long name derived from the timezone's fallback name, such as "United States (Los Angeles)."
    static final TimeZone
    The immutable GMT (=UTC) time zone.
    static final int
    A style specifier for getDisplayName() indicating a long name, such as "Pacific Standard Time."
    static final int
    A style specifier for getDisplayName() indicating a long generic name, such as "Pacific Time."
    static final int
    A style specifier for getDisplayName() indicating a long name derived from the timezone's offset, such as "GMT-08:00."
    static final int
    A style specifier for getDisplayName() indicating a short name, such as "PST."
    static final int
    A style specifier for getDisplayName() indicating a short name derived from the timezone's short standard or daylight timezone name ignoring commonlyUsed, such as "PDT."
    static final int
    A style specifier for getDisplayName() indicating a short generic name, such as "PT."
    static final int
    A style specifier for getDisplayName() indicating a short name derived from the timezone's offset, such as "-0800."
    static final int
    A time zone implementation type indicating ICU's own TimeZone used by getTimeZone, setDefaultTimeZoneType and getDefaultTimeZoneType.
    static final int
    A time zone implementation type indicating the TimeZone used by getTimeZone, setDefaultTimeZoneType and getDefaultTimeZoneType.
    static final TimeZone
    The immutable (frozen) "unknown" time zone.
    static final String
    The time zone ID reserved for unknown time zone.
  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
     
    Default constructor.
    protected
    Deprecated.
    This API is ICU internal only.
  • Method Summary

    Modifier and Type
    Method
    Description
    Overrides clone.
    Provides for the clone operation.
    static int
    Returns the number of IDs in the equivalency group that includes the given ID.
    boolean
    Overrides equals.
    static TimeZone
    Deprecated.
    This API is ICU internal only.
    static TimeZone
    Deprecated.
    This API is ICU internal only.
    Freezes the object.
    static String[]
    Return a new String array containing all system TimeZone IDs.
    static String[]
    getAvailableIDs(int rawOffset)
    Return a new String array containing all system TimeZone IDs with the given raw offset from GMT.
    static Set<String>
    Returns a set of time zone ID strings with the given filter conditions.
    static String[]
    Return a new String array containing all system TimeZone IDs associated with the given country.
    static String
    Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
    static String
    getCanonicalID(String id, boolean[] isSystemID)
    Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
    static TimeZone
    Gets the default TimeZone for this host.
    static int
    Returns the default time zone type currently used.
    final String
    Returns a name of this time zone suitable for presentation to the user in the default DISPLAY locale.
    final String
    getDisplayName(boolean daylight, int style)
    Returns a name of this time zone suitable for presentation to the user in the default DISPLAY locale.
    getDisplayName(boolean daylight, int style, ULocale locale)
    Returns a name of this time zone suitable for presentation to the user in the specified locale.
    getDisplayName(boolean daylight, int style, Locale locale)
    Returns a name of this time zone suitable for presentation to the user in the specified locale.
    final String
    Returns a name of this time zone suitable for presentation to the user in the specified locale.
    final String
    Returns a name of this time zone suitable for presentation to the user in the specified locale.
    int
    Returns the amount of time to be added to local standard time to get local wall clock time.
    static String
    getEquivalentID(String id, int index)
    Returns an ID in the equivalency group that includes the given ID.
    static TimeZone
    Gets the TimeZone for the given ID.
    Gets the ID of this time zone.
    static String
    Converts a Windows time zone ID to an equivalent system time zone ID for a region.
    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.
    void
    getOffset(long date, boolean local, int[] offsets)
    Returns the time zone raw and GMT offset for the given moment in time.
    abstract int
    Gets unmodified offset, NOT modified in case of daylight savings.
    static String
    Returns the region code associated with the given system time zone ID.
    static TimeZone
    Gets the TimeZone for the given ID.
    static TimeZone
    getTimeZone(String ID, int type)
    Gets the TimeZone for the given ID and the timezone type.
    static String
    Returns the time zone data version currently used by ICU.
    static String
    Converts a system time zone ID to an equivalent Windows time zone ID.
    int
    Overrides hashCode.
    boolean
    Returns true if this zone has the same rule and offset as another zone.
    abstract boolean
    Queries if the given date is in daylight savings time in this time zone.
    boolean
    Determines whether the object has been frozen or not.
    boolean
    Queries if this time zone is in daylight saving time or will observe daylight saving time at any future time.
    static void
    Sets the TimeZone that is returned by the getDefault method.
    static void
    Sets the default time zone type used by getTimeZone.
    static void
    Deprecated.
    This API is ICU internal only.
    void
    Sets the time zone ID.
    abstract void
    setRawOffset(int offsetMillis)
    Sets the base time zone offset to GMT.
    abstract boolean
    Queries if this time zone uses daylight savings time.

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • TIMEZONE_ICU

      public static final int TIMEZONE_ICU
      A time zone implementation type indicating ICU's own TimeZone used by getTimeZone, setDefaultTimeZoneType and getDefaultTimeZoneType.
      See Also:
    • TIMEZONE_JDK

      public static final int TIMEZONE_JDK
      A time zone implementation type indicating the TimeZone used by getTimeZone, setDefaultTimeZoneType and getDefaultTimeZoneType.
      See Also:
    • SHORT

      public static final int SHORT
      A style specifier for getDisplayName() indicating a short name, such as "PST."
      See Also:
    • LONG

      public static final int LONG
      A style specifier for getDisplayName() indicating a long name, such as "Pacific Standard Time."
      See Also:
    • SHORT_GENERIC

      public static final int SHORT_GENERIC
      A style specifier for getDisplayName() indicating a short generic name, such as "PT."
      See Also:
    • LONG_GENERIC

      public static final int LONG_GENERIC
      A style specifier for getDisplayName() indicating a long generic name, such as "Pacific Time."
      See Also:
    • SHORT_GMT

      public static final int SHORT_GMT
      A style specifier for getDisplayName() indicating a short name derived from the timezone's offset, such as "-0800."
      See Also:
    • LONG_GMT

      public static final int LONG_GMT
      A style specifier for getDisplayName() indicating a long name derived from the timezone's offset, such as "GMT-08:00."
      See Also:
    • SHORT_COMMONLY_USED

      public static final int SHORT_COMMONLY_USED
      A style specifier for getDisplayName() indicating a short name derived from the timezone's short standard or daylight timezone name ignoring commonlyUsed, such as "PDT."
      See Also:
    • GENERIC_LOCATION

      public static final int GENERIC_LOCATION
      A style specifier for getDisplayName() indicating a long name derived from the timezone's fallback name, such as "United States (Los Angeles)."
      See Also:
    • UNKNOWN_ZONE_ID

      public static final String UNKNOWN_ZONE_ID
      The time zone ID reserved for unknown time zone.
      See Also:
    • UNKNOWN_ZONE

      public static final TimeZone UNKNOWN_ZONE
      The immutable (frozen) "unknown" time zone. It behaves like the GMT/UTC time zone but has the UNKNOWN_ZONE_ID = "Etc/Unknown". getTimeZone(String) returns a mutable clone of this time zone if the input ID is not recognized.
      See Also:
    • GMT_ZONE

      public static final TimeZone GMT_ZONE
      The immutable GMT (=UTC) time zone. Its ID is "Etc/GMT".
  • Constructor Details

    • TimeZone

      public TimeZone()
      Default constructor. (For invocation by subclass constructors, typically implicit.)
    • TimeZone

      @Deprecated protected TimeZone(String ID)
      Deprecated.
      This API is ICU internal only.
      Constructing a TimeZone with the given time zone ID.
      Parameters:
      ID - the time zone ID.
  • 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.
      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 millis in day in standard local time.
      Returns:
      the offset to add to GMT to get local time.
    • 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.
      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.
      See Also:
    • getOffset

      public void getOffset(long date, boolean local, int[] offsets)
      Returns the time zone raw and GMT offset for the given moment in time. Upon return, local-millis = GMT-millis + rawOffset + dstOffset. All computations are performed in the proleptic Gregorian calendar. The default implementation in the TimeZone class delegates to the 8-argument getOffset().
      Parameters:
      date - moment in time for which to return offsets, in units of milliseconds from January 1, 1970 0:00 GMT, either GMT time or local wall time, depending on local.
      local - if true, date is local wall time; otherwise it is in GMT time.
      offsets - output parameter to receive the raw offset, that is, the offset not including DST adjustments, in offsets[0], and the DST offset, that is, the offset to be added to rawOffset to obtain the total offset between local and GMT time, in offsets[1]. If DST is not in effect, the DST offset is zero; otherwise it is a positive value, typically one hour.
    • 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.
      Parameters:
      offsetMillis - the given base time zone offset to GMT.
    • getRawOffset

      public abstract int getRawOffset()
      Gets unmodified offset, NOT modified in case of daylight savings. This is the offset to add to UTC to get local time.
      Returns:
      the unmodified offset to add to UTC to get local time.
    • 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.
      Parameters:
      ID - the new time zone ID.
    • getDisplayName

      public final String getDisplayName()
      Returns a name of this time zone suitable for presentation to the user in the default DISPLAY locale. This method returns the long generic name. If the display name is not available for the locale, a fallback based on the country, city, or time zone id will be used.
      Returns:
      the human-readable name of this time zone in the default locale.
      See Also:
    • getDisplayName

      public final String getDisplayName(Locale locale)
      Returns a name of this time zone suitable for presentation to the user in the specified locale. This method returns the long generic name. If the display name is not available for the locale, a fallback based on the country, city, or time zone id will be used.
      Parameters:
      locale - the locale in which to supply the display name.
      Returns:
      the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized.
    • getDisplayName

      public final String getDisplayName(ULocale locale)
      Returns a name of this time zone suitable for presentation to the user in the specified locale. This method returns the long name, not including daylight savings. If the display name is not available for the locale, a fallback based on the country, city, or time zone id will be used.
      Parameters:
      locale - the ulocale in which to supply the display name.
      Returns:
      the human-readable name of this time zone in the given locale or in the default ulocale if the given ulocale is not recognized.
    • getDisplayName

      public final String getDisplayName(boolean daylight, int style)
      Returns a name of this time zone suitable for presentation to the user in the default DISPLAY locale. If the display name is not available for the locale, then this method returns a string in the localized GMT offset format such as GMT[+-]HH:mm.
      Parameters:
      daylight - if true, return the daylight savings name.
      style - the output style of the display name. Valid styles are SHORT, LONG, SHORT_GENERIC, LONG_GENERIC, SHORT_GMT, LONG_GMT, SHORT_COMMONLY_USED or GENERIC_LOCATION.
      Returns:
      the human-readable name of this time zone in the default locale.
      See Also:
    • getDisplayName

      public String getDisplayName(boolean daylight, int style, Locale locale)
      Returns a name of this time zone suitable for presentation to the user in the specified locale. If the display name is not available for the locale, then this method returns a string in the localized GMT offset format such as GMT[+-]HH:mm.
      Parameters:
      daylight - if true, return the daylight savings name.
      style - the output style of the display name. Valid styles are SHORT, LONG, SHORT_GENERIC, LONG_GENERIC, SHORT_GMT, LONG_GMT, SHORT_COMMONLY_USED or GENERIC_LOCATION.
      locale - the locale in which to supply the display name.
      Returns:
      the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized.
      Throws:
      IllegalArgumentException - style is invalid.
    • getDisplayName

      public String getDisplayName(boolean daylight, int style, ULocale locale)
      Returns a name of this time zone suitable for presentation to the user in the specified locale. If the display name is not available for the locale, then this method returns a string in the localized GMT offset format such as GMT[+-]HH:mm.
      Parameters:
      daylight - if true, return the daylight savings name.
      style - the output style of the display name. Valid styles are SHORT, LONG, SHORT_GENERIC, LONG_GENERIC, SHORT_GMT, LONG_GMT, SHORT_COMMONLY_USED or GENERIC_LOCATION.
      locale - the locale in which to supply the display name.
      Returns:
      the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized.
      Throws:
      IllegalArgumentException - style is invalid.
    • 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 always returns 3600000 milliseconds (i.e., one hour) if this time zone observes Daylight Saving Time. Otherwise, 0 (zero) is returned.

      If an underlying TimeZone implementation subclass supports historical Daylight Saving Time changes, this method returns the known latest daylight saving value.

      Returns:
      the amount of saving time in milliseconds
    • useDaylightTime

      public abstract boolean useDaylightTime()
      Queries if this time zone uses daylight savings time.
      Returns:
      true if this time zone uses daylight savings time, false, otherwise.

      Note:The default implementation of ICU TimeZone uses the tz database, which supports historic rule changes, for system time zones. With the implementation, there are time zones that used daylight savings time in the past, but no longer used currently. For example, Asia/Tokyo has never used daylight savings time since 1951. Most clients would expect that this method to return false for such case. The default implementation of this method returns true when the time zone uses daylight savings time in the current (Gregorian) calendar year.

    • observesDaylightTime

      public boolean observesDaylightTime()
      Queries if this time zone is in daylight saving time or will observe daylight saving time at any future time.

      The default implementation in this class returns true if useDaylightTime() or inDaylightTime(new Date()) returns true.

      Note: This method was added for TimeZone compatibility support. The TimeZone.useDaylightTime() method only checks the last known rule(s), therefore it may return false even the zone observes daylight saving time currently. TimeZone added observesDaylightTime() to resolve the issue. In ICU, useDaylightTime() works differently. The ICU implementation checks if the zone uses daylight saving time in the current calendar year. Therefore, it will never return false if daylight saving time is currently used.

      ICU's TimeZone subclass implementations override this method to support the same behavior with TimeZone.observesDaylightTime(). Unlike useDaylightTime(), the implementation does not take past daylight saving time into account, so that this method may return false even when useDaylightTime() returns true.

      Returns:
      true if this time zone is in daylight saving time or will observe daylight saving time at any future time.
      See Also:
    • inDaylightTime

      public abstract boolean inDaylightTime(Date date)
      Queries if the given date is in daylight savings time in this time zone.
      Parameters:
      date - the given Date.
      Returns:
      true if the given date is in daylight savings time, false, otherwise.
    • getTimeZone

      public static TimeZone getTimeZone(String ID)
      Gets the TimeZone for the given ID.
      Parameters:
      ID - the ID for a TimeZone, such as "America/Los_Angeles", or a custom ID such as "GMT-8:00". Note that the support of abbreviations, such as "PST", is for JDK 1.1.x compatibility only and full names should be used.
      Returns:
      the specified TimeZone, or a mutable clone of the UNKNOWN_ZONE if the given ID cannot be understood or if the given ID is "Etc/Unknown".
      See Also:
    • getFrozenTimeZone

      public static TimeZone getFrozenTimeZone(String ID)
      Gets the TimeZone for the given ID. The instance of TimeZone returned by this method is immutable. Any methods mutate the instance(setID(String), setRawOffset(int)) will throw UnsupportedOperationException upon its invocation.
      Parameters:
      ID - the ID for a TimeZone, such as "America/Los_Angeles", or a custom ID such as "GMT-8:00". Note that the support of abbreviations, such as "PST", is for JDK 1.1.x compatibility only and full names should be used.
      Returns:
      the specified TimeZone, or the UNKNOWN_ZONE if the given ID cannot be understood.
      See Also:
    • getTimeZone

      public static TimeZone getTimeZone(String ID, int type)
      Gets the TimeZone for the given ID and the timezone type.
      Parameters:
      ID - the ID for a TimeZone, such as "America/Los_Angeles", or a custom ID such as "GMT-8:00". Note that the support of abbreviations, such as "PST", is for JDK 1.1.x compatibility only and full names should be used.
      type - Time zone type, either TIMEZONE_ICU or TIMEZONE_JDK.
      Returns:
      the specified TimeZone, or a mutable clone of the UNKNOWN_ZONE if the given ID cannot be understood or if the given ID is "Etc/Unknown".
      See Also:
    • setDefaultTimeZoneType

      public static void setDefaultTimeZoneType(int type)
      Sets the default time zone type used by getTimeZone.
      Parameters:
      type - time zone type, either TIMEZONE_ICU or TIMEZONE_JDK.
    • getDefaultTimeZoneType

      public static int getDefaultTimeZoneType()
      Returns the default time zone type currently used.
      Returns:
      The default time zone type, either TIMEZONE_ICU or TIMEZONE_JDK.
    • getAvailableIDs

      public static Set<String> getAvailableIDs(TimeZone.SystemTimeZoneType zoneType, String region, Integer rawOffset)
      Returns a set of time zone ID strings with the given filter conditions.

      Note:A Set returned by this method is immutable.

      Parameters:
      zoneType - The system time zone type.
      region - The ISO 3166 two-letter country code or UN M.49 three-digit area code. When null, no filtering done by region.
      rawOffset - An offset from GMT in milliseconds, ignoring the effect of daylight savings time, if any. When null, no filtering done by zone offset.
      Returns:
      an immutable set of system time zone IDs.
      See Also:
    • getAvailableIDs

      public static String[] getAvailableIDs(int rawOffset)
      Return a new String array containing all system TimeZone IDs with the given raw offset from GMT. These IDs may be passed to get() to construct the corresponding TimeZone object.
      Parameters:
      rawOffset - the offset in milliseconds from GMT
      Returns:
      an array of IDs for system TimeZones with the given raw offset. If there are none, return a zero-length array.
      See Also:
    • getAvailableIDs

      public static String[] getAvailableIDs(String country)
      Return a new String array containing all system TimeZone IDs associated with the given country. These IDs may be passed to get() to construct the corresponding TimeZone object.
      Parameters:
      country - a two-letter ISO 3166 country code, or null to return zones not associated with any country
      Returns:
      an array of IDs for system TimeZones in the given country. If there are none, return a zero-length array.
      See Also:
    • getAvailableIDs

      public static String[] getAvailableIDs()
      Return a new String array containing all system TimeZone IDs. These IDs (and only these IDs) may be passed to get() to construct the corresponding TimeZone object.
      Returns:
      an array of all system TimeZone IDs
      See Also:
    • countEquivalentIDs

      public static int countEquivalentIDs(String id)
      Returns the number of IDs in the equivalency group that includes the given ID. An equivalency group contains zones that have the same GMT offset and rules.

      The returned count includes the given ID; it is always >= 1 for valid IDs. The given ID must be a system time zone. If it is not, returns zero.

      Parameters:
      id - a system time zone ID
      Returns:
      the number of zones in the equivalency group containing 'id', or zero if 'id' is not a valid system ID
      See Also:
    • getEquivalentID

      public static String getEquivalentID(String id, int index)
      Returns an ID in the equivalency group that includes the given ID. An equivalency group contains zones that have the same GMT offset and rules.

      The given index must be in the range 0..n-1, where n is the value returned by countEquivalentIDs(id). For some value of 'index', the returned value will be equal to the given id. If the given id is not a valid system time zone, or if 'index' is out of range, then returns an empty string.

      Parameters:
      id - a system time zone ID
      index - a value from 0 to n-1, where n is the value returned by countEquivalentIDs(id)
      Returns:
      the ID of the index-th zone in the equivalency group containing 'id', or an empty string if 'id' is not a valid system ID or 'index' is out of range
      See Also:
    • forULocaleOrDefault

      @Deprecated public static TimeZone forULocaleOrDefault(ULocale locale)
      Deprecated.
      This API is ICU internal only.
      If the locale contains the timezone keyword, creates a copy of that TimeZone. Otherwise, create the default TimeZone.
      Parameters:
      locale - a locale which may contains 'timezone' keyword/value.
      Returns:
      A TimeZone. Clients are responsible for deleting the TimeZone object returned.
    • forLocaleOrDefault

      @Deprecated public static TimeZone forLocaleOrDefault(Locale locale)
      Deprecated.
      This API is ICU internal only.
      If the locale contains the timezone keyword, creates a copy of that TimeZone. Otherwise, create the default TimeZone.
      Parameters:
      locale - a locale which may contains 'timezone' keyword/value.
      Returns:
      A TimeZone. Clients are responsible for deleting the TimeZone object returned.
    • getDefault

      public static TimeZone getDefault()
      Gets the default TimeZone for this host. The source of the default TimeZone may vary with implementation.
      Returns:
      a default TimeZone.
    • setDefault

      public static void setDefault(TimeZone tz)
      Sets the TimeZone that is returned by the getDefault method. This method also sets a Java TimeZone equivalent to the input tz as the JVM's default time zone if not null. If tz is null, next getDefault() method invocation will reset the default time zone synchronized with the JVM's default at that time.
      Parameters:
      tz - the new default time zone
    • setICUDefault

      @Deprecated public static void setICUDefault(TimeZone tz)
      Deprecated.
      This API is ICU internal only.
      Sets the TimeZone that is returned by the getDefault method. If tz is null, next getDefault() method invocation will reset the default time zone synchronized with the JVM's default at that time. Unlike setDefault(TimeZone), this method does not change the JVM's default time zone.
      Parameters:
      tz - the new default time zone
    • 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
    • clone

      public Object clone()
      Overrides clone.
      Overrides:
      clone in class Object
    • equals

      public boolean equals(Object obj)
      Overrides equals.
      Overrides:
      equals in class Object
      Returns:
      true if this object is the same as the obj argument; false otherwise.
    • hashCode

      public int hashCode()
      Overrides hashCode.
      Overrides:
      hashCode in class Object
      Returns:
      a hash code value for this object.
    • getTZDataVersion

      public static String getTZDataVersion()
      Returns the time zone data version currently used by ICU.
      Returns:
      the version string, such as "2007f"
      Throws:
      MissingResourceException - if ICU time zone resource bundle is missing or the version information is not available.
    • getCanonicalID

      public static String getCanonicalID(String id)
      Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
      Parameters:
      id - The input time zone ID to be canonicalized.
      Returns:
      The canonical system time zone ID or the custom time zone ID in normalized format for the given time zone ID. When the given time zone ID is neither a known system time zone ID nor a valid custom time zone ID, null is returned.
    • getCanonicalID

      public static String getCanonicalID(String id, boolean[] isSystemID)
      Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
      Parameters:
      id - The input time zone ID to be canonicalized.
      isSystemID - When non-null boolean array is specified and the given ID is a known system time zone ID, true is set to isSystemID[0]
      Returns:
      The canonical system time zone ID or the custom time zone ID in normalized format for the given time zone ID. When the given time zone ID is neither a known system time zone ID nor a valid custom time zone ID, null is returned.
    • getRegion

      public static String getRegion(String id)
      Returns the region code associated with the given system time zone ID. The region code is either ISO 3166 2-letter country code or UN M.49 3-digit area code. When the time zone is not associated with a specific location, for example - "Etc/UTC", "EST5EDT", then this method returns "001" (UN M.49 area code for World).
      Parameters:
      id - the system time zone ID.
      Returns:
      the region code associated with the given system time zone ID.
      Throws:
      IllegalArgumentException - if id is not a known system ID.
      See Also:
    • getWindowsID

      public static String getWindowsID(String id)
      Converts a system time zone ID to an equivalent Windows time zone ID. For example, Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles".

      There are system time zones that cannot be mapped to Windows zones. When the input system time zone ID is unknown or unmappable to a Windows time zone, then this method returns null.

      This implementation utilizes Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes, please read the ICU user guide section Updating the Time Zone Data.

      Parameters:
      id - A system time zone ID
      Returns:
      A Windows time zone ID mapped from the input system time zone ID, or null when the input ID is unknown or unmappable.
      See Also:
    • getIDForWindowsID

      public static String getIDForWindowsID(String winid, String region)
      Converts a Windows time zone ID to an equivalent system time zone ID for a region. For example, system time zone ID "America/Los_Angeles" is returned for input Windows ID "Pacific Standard Time" and region "US" (or null), "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and region "CA".

      Not all Windows time zones can be mapped to system time zones. When the input Windows time zone ID is unknown or unmappable to a system time zone, then this method returns null.

      This implementation utilizes Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes, please read the ICU user guide section Updating the Time Zone Data.

      Parameters:
      winid - A Windows time zone ID
      region - A region code, or null if no regional preference.
      Returns:
      A system time zone ID mapped from the input Windows time zone ID, or null when the input ID is unknown or unmappable.
      See Also:
    • isFrozen

      public boolean isFrozen()
      Determines whether the object has been frozen or not.
      Specified by:
      isFrozen in interface Freezable<TimeZone>
    • freeze

      public TimeZone freeze()
      Freezes the object.
      Specified by:
      freeze in interface Freezable<TimeZone>
      Returns:
      the object itself.
    • cloneAsThawed

      public TimeZone cloneAsThawed()
      Provides for the clone operation. Any clone is initially unfrozen.
      Specified by:
      cloneAsThawed in interface Freezable<TimeZone>