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 /*************************************************************************

 * Copyright (c) 1997-2013, International Business Machines Corporation

 * and others. All Rights Reserved.

 **************************************************************************

 *

 * File TIMEZONE.H

 *

 * Modification History:

 *

 *   Date        Name        Description

 *   04/21/97    aliu        Overhauled header.

 *   07/09/97    helena      Changed createInstance to createDefault.

 *   08/06/97    aliu        Removed dependency on internal header for Hashtable.

 *   08/10/98    stephen        Changed getDisplayName() API conventions to match

 *   08/19/98    stephen        Changed createTimeZone() to never return 0

 *   09/02/98    stephen        Sync to JDK 1.2 8/31

 *                            - Added getOffset(... monthlen ...)

 *                            - Added hasSameRules()

 *   09/15/98    stephen        Added getStaticClassID

 *   12/03/99    aliu        Moved data out of static table into icudata.dll.

 *                           Hashtable replaced by new static data structures.

 *   12/14/99    aliu        Made GMT public.

 *   08/15/01    grhoten     Made GMT private and added the getGMT() function

 **************************************************************************

 */

 #ifndef TIMEZONE_H

 #define TIMEZONE_H

 #include "unicode/utypes.h"

 /**

  * \file 

  * \brief C++ API: TimeZone object

  */

 #if !UCONFIG_NO_FORMATTING

 #include "unicode/uobject.h"

 #include "unicode/unistr.h"

 #include "unicode/ures.h"

 #include "unicode/ucal.h"

 U_NAMESPACE_BEGIN

 class StringEnumeration;

 /**

  *

  * <code>TimeZone</code> represents a time zone offset, and also figures out daylight

  * savings.

  *

  * <p>

  * Typically, you get a <code>TimeZone</code> using <code>createDefault</code>

  * which creates a <code>TimeZone</code> based on the time zone where the program

  * is running. For example, for a program running in Japan, <code>createDefault</code>

  * creates a <code>TimeZone</code> object based on Japanese Standard Time.

  *

  * <p>

  * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along

  * with a time zone ID. For instance, the time zone ID for the US Pacific

  * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object

  * with:

  * \htmlonly<blockquote>\endhtmlonly

  * <pre>

  * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles");

  * </pre>

  * \htmlonly</blockquote>\endhtmlonly

  * You can use <code>getAvailableIDs</code> 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 <code>TimeZone</code>.

  * 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:

  *

  * \htmlonly<blockquote>\endhtmlonly

  * <pre>

  * GMT[+|-]hh[[:]mm]

  * </pre>

  * \htmlonly</blockquote>\endhtmlonly

  *

  * For example, you might specify GMT+14:00 as a custom

  * time zone ID.  The <code>TimeZone</code> 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,

  * <code>getCanonicalID</code> can also be used to

  * normalize a custom time zone ID.

  *

  * TimeZone is an abstract class representing a time zone.  A TimeZone is needed for

  * Calendar to produce local time for a particular time zone.  A TimeZone comprises

  * three basic pieces of information:

  * <ul>

  *    <li>A time zone offset; that, is the number of milliseconds to add or subtract

  *      from a time expressed in terms of GMT to convert it to the same time in that

  *      time zone (without taking daylight savings time into account).</li>

  *    <li>Logic necessary to take daylight savings time into account if daylight savings

  *      time is observed in that time zone (e.g., the days and hours on which daylight

  *      savings time begins and ends).</li>

  *    <li>An ID.  This is a text string that uniquely identifies the time zone.</li>

  * </ul>

  *

  * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle

  * daylight savings time and GMT offset in different ways.  Currently we have the following

  * TimeZone subclasses: RuleBasedTimeZone, SimpleTimeZone, and VTimeZone.)

  * <P>

  * The TimeZone class contains a static list containing a TimeZone object for every

  * combination of GMT offset and daylight-savings time rules currently in use in the

  * world, each with a unique ID.  Each ID consists of a region (usually a continent or

  * ocean) and a city in that region, separated by a slash, (for example, US Pacific

  * Time is "America/Los_Angeles.")  Because older versions of this class used

  * three- or four-letter abbreviations instead, there is also a table that maps the older

  * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles").

  * Anywhere the API requires an ID, you can use either form.

  * <P>

  * To create a new TimeZone, you call the factory function TimeZone::createTimeZone()

  * and pass it a time zone ID.  You can use the createEnumeration() function to

  * obtain a list of all the time zone IDs recognized by createTimeZone().

  * <P>

  * You can also use TimeZone::createDefault() to create a TimeZone.  This function uses

  * platform-specific APIs to produce a TimeZone for the time zone corresponding to

  * the client's computer's physical location.  For example, if you're in Japan (assuming

  * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone

  * for Japanese Standard Time ("Asia/Tokyo").

  */

 class U_I18N_API TimeZone : public UObject {

 public:

     /**

      * @stable ICU 2.0

      */

     virtual ~TimeZone();

     /**

      * Returns the "unknown" time zone.

      * It behaves like the GMT/UTC time zone but has the

      * <code>UCAL_UNKNOWN_ZONE_ID</code> = "Etc/Unknown".

      * createTimeZone() returns a mutable clone of this time zone if the input ID is not recognized.

      *

      * @return the "unknown" time zone.

      * @see UCAL_UNKNOWN_ZONE_ID

      * @see createTimeZone

      * @see getGMT

      * @stable ICU 49

      */

     static const TimeZone& U_EXPORT2 getUnknown();

     /**

      * The GMT (=UTC) time zone has a raw offset of zero and does not use daylight

      * savings time. This is a commonly used time zone.

      *

      * <p>Note: For backward compatibility reason, the ID used by the time

      * zone returned by this method is "GMT", although the ICU's canonical

      * ID for the GMT time zone is "Etc/GMT".

      *

      * @return the GMT/UTC time zone.

      * @see getUnknown

      * @stable ICU 2.0

      */

     static const TimeZone* U_EXPORT2 getGMT(void);

     /**

      * Creates a <code>TimeZone</code> for the given ID.

      * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles",

      * or a custom ID such as "GMT-8:00".

      * @return the specified <code>TimeZone</code>, or a mutable clone of getUnknown()

      * if the given ID cannot be understood or if the given ID is "Etc/Unknown".

      * The return result is guaranteed to be non-NULL.

      * If you require that the specific zone asked for be returned,

      * compare the result with getUnknown() or check the ID of the return result.

      * @stable ICU 2.0

      */

     static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID);

     /**

      * Returns an enumeration over system time zone IDs with the given

      * filter conditions.

      * @param zoneType      The system time zone type.

      * @param region        The ISO 3166 two-letter country code or UN M.49

      *                      three-digit area code. When NULL, no filtering

      *                      done by region. 

      * @param rawOffset     An offset from GMT in milliseconds, ignoring

      *                      the effect of daylight savings time, if any.

      *                      When NULL, no filtering done by zone offset. 

      * @param ec            Output param to filled in with a success or

      *                      an error.

      * @return an enumeration object, owned by the caller.

      * @stable ICU 4.8

      */

     static StringEnumeration* U_EXPORT2 createTimeZoneIDEnumeration(

         USystemTimeZoneType zoneType,

         const char* region,

         const int32_t* rawOffset,

         UErrorCode& ec);

     /**

      * Returns an enumeration over all recognized time zone IDs. (i.e.,

      * all strings that createTimeZone() accepts)

      *

      * @return an enumeration object, owned by the caller.

      * @stable ICU 2.4

      */

     static StringEnumeration* U_EXPORT2 createEnumeration();

     /**

      * Returns an enumeration over time zone IDs with a given raw

      * offset from GMT.  There may be several times zones with the

      * same GMT offset that differ in the way they handle daylight

      * savings time.  For example, the state of Arizona doesn't

      * observe daylight savings time.  If you ask for the time zone

      * IDs corresponding to GMT-7:00, you'll get back an enumeration

      * over two time zone IDs: "America/Denver," which corresponds to

      * Mountain Standard Time in the winter and Mountain Daylight Time

      * in the summer, and "America/Phoenix", which corresponds to

      * Mountain Standard Time year-round, even in the summer.

      *

      * @param rawOffset an offset from GMT in milliseconds, ignoring

      * the effect of daylight savings time, if any

      * @return an enumeration object, owned by the caller

      * @stable ICU 2.4

      */

     static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset);

     /**

      * Returns an enumeration over time zone IDs associated with the

      * given country.  Some zones are affiliated with no country

      * (e.g., "UTC"); these may also be retrieved, as a group.

      *

      * @param country The ISO 3166 two-letter country code, or NULL to

      * retrieve zones not affiliated with any country.

      * @return an enumeration object, owned by the caller

      * @stable ICU 2.4

      */

     static StringEnumeration* U_EXPORT2 createEnumeration(const char* country);

     /**

      * 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.

      *

      * <p>The returned count includes the given ID; it is always >= 1.

      * The given ID must be a system time zone.  If it is not, returns

      * zero.

      * @param id a system time zone ID

      * @return the number of zones in the equivalency group containing

      * 'id', or zero if 'id' is not a valid system ID

      * @see #getEquivalentID

      * @stable ICU 2.0

      */

     static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id);

     /**

      * 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.

      *

      * <p>The given index must be in the range 0..n-1, where n is the

      * value returned by <code>countEquivalentIDs(id)</code>.  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.

      * @param id a system time zone ID

      * @param index a value from 0 to n-1, where n is the value

      * returned by <code>countEquivalentIDs(id)</code>

      * @return 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 #countEquivalentIDs

      * @stable ICU 2.0

      */

     static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id,

                                                int32_t index);

     /**

      * Creates a new copy of the default TimeZone for this host. Unless the default time

      * zone has already been set using adoptDefault() or setDefault(), the default is

      * determined by querying the system using methods in TPlatformUtilities. If the

      * system routines fail, or if they specify a TimeZone or TimeZone offset which is not

      * recognized, the TimeZone indicated by the ID kLastResortID is instantiated

      * and made the default.

      *

      * @return   A default TimeZone. Clients are responsible for deleting the time zone

      *           object returned.

      * @stable ICU 2.0

      */

     static TimeZone* U_EXPORT2 createDefault(void);

     /**

      * Sets the default time zone (i.e., what's returned by createDefault()) to be the

      * specified time zone.  If NULL is specified for the time zone, the default time

      * zone is set to the default host time zone.  This call adopts the TimeZone object

      * passed in; the client is no longer responsible for deleting it.

      *

      * <p>This function is not thread safe. It is an error for multiple threads

      * to concurrently attempt to set the default time zone, or for any thread

      * to attempt to reference the default zone while another thread is setting it.

      *

      * @param zone  A pointer to the new TimeZone object to use as the default.

      * @stable ICU 2.0

      */

     static void U_EXPORT2 adoptDefault(TimeZone* zone);

 #ifndef U_HIDE_SYSTEM_API

     /**

      * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted;

      * the caller remains responsible for deleting it.

      *

      * <p>See the thread safety note under adoptDefault().

      *

      * @param zone  The given timezone.

      * @system

      * @stable ICU 2.0

      */

     static void U_EXPORT2 setDefault(const TimeZone& zone);

 #endif  /* U_HIDE_SYSTEM_API */

     /**

      * Returns the timezone data version currently used by ICU.

      * @param status Output param to filled in with a success or an error.

      * @return the version string, such as "2007f"

      * @stable ICU 3.8

      */

     static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status);

     /**

      * Returns the canonical system timezone ID or the normalized

      * custom time zone ID for the given time zone ID.

      * @param id            The input time zone ID to be canonicalized.

      * @param canonicalID   Receives the canonical system time zone ID

      *                      or the custom time zone ID in normalized format.

      * @param status        Recevies the status.  When the given time zone ID

      *                      is neither a known system time zone ID nor a

      *                      valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR

      *                      is set.

      * @return A reference to the result.

      * @stable ICU 4.0

      */

     static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,

         UnicodeString& canonicalID, UErrorCode& status);

     /**

      * Returns the canonical system time zone ID or the normalized

      * custom time zone ID for the given time zone ID.

      * @param id            The input time zone ID to be canonicalized.

      * @param canonicalID   Receives the canonical system time zone ID

      *                      or the custom time zone ID in normalized format.

      * @param isSystemID    Receives if the given ID is a known system

      *                      time zone ID.

      * @param status        Recevies the status.  When the given time zone ID

      *                      is neither a known system time zone ID nor a

      *                      valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR

      *                      is set.

      * @return A reference to the result.

      * @stable ICU 4.0

      */

     static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,

         UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status);

 #ifndef U_HIDE_DRAFT_API

     /**

     * 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".

     *

     * <p>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 the result will be

     * empty, but the operation itself remains successful (no error status set on return).

     *

     * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">

     * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,

     * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">

     * Updating the Time Zone Data</a>.

     *

     * @param id        A system time zone ID.

     * @param winid     Receives a Windows time zone ID. When the input system time zone ID is unknown

     *                  or unmappable to a Windows time zone ID, then an empty string is set on return.

     * @param status    Receives the status.

     * @return          A reference to the result (<code>winid</code>).

     * @see getIDForWindowsID

     *

     * @draft ICU 52

     */

     static UnicodeString& U_EXPORT2 getWindowsID(const UnicodeString& id,

         UnicodeString& winid, UErrorCode& status);

     /**

     * 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 <code>null</code>),

     * "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and

     * region "CA".

     *

     * <p>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 the result

     * will be empty, but the operation itself remains successful (no error status set on return).

     *

     * <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">

     * Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,

     * please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">

     * Updating the Time Zone Data</a>.

     *

     * @param winid     A Windows time zone ID.

     * @param region    A null-terminated region code, or <code>NULL</code> if no regional preference.

     * @param id        Receives a system time zone ID. When the input Windows time zone ID is unknown

     *                  or unmappable to a system time zone ID, then an empty string is set on return.

     * @param status    Receives the status.

     * @return          A reference to the result (<code>id</code>).

     * @see getWindowsID

     *

     * @draft ICU 52

     */

     static UnicodeString& U_EXPORT2 getIDForWindowsID(const UnicodeString& winid, const char* region,

         UnicodeString& id, UErrorCode& status);

 #endif /* U_HIDE_DRAFT_API */

     /**

      * Returns true if the two TimeZones are equal.  (The TimeZone version only compares

      * IDs, but subclasses are expected to also compare the fields they add.)

      *

      * @param that  The TimeZone object to be compared with.

      * @return      True if the given TimeZone is equal to this TimeZone; false

      *              otherwise.

      * @stable ICU 2.0

      */

     virtual UBool operator==(const TimeZone& that) const;

     /**

      * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns

      * false.

      *

      * @param that  The TimeZone object to be compared with.

      * @return      True if the given TimeZone is not equal to this TimeZone; false

      *              otherwise.

      * @stable ICU 2.0

      */

     UBool operator!=(const TimeZone& that) const {return !operator==(that);}

     /**

      * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add

      * to GMT to get local time in this time zone, taking daylight savings time into

      * account) as of a particular reference date.  The reference date is used to determine

      * whether daylight savings time is in effect and needs to be figured into the offset

      * that is returned (in other words, what is the adjusted GMT offset in this time zone

      * at this particular date and time?).  For the time zones produced by createTimeZone(),

      * the reference data is specified according to the Gregorian calendar, and the date

      * and time fields are local standard time.

      *

      * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,

      * which returns both the raw and the DST offset for a given time. This method

      * is retained only for backward compatibility.

      *

      * @param era        The reference date's era

      * @param year       The reference date's year

      * @param month      The reference date's month (0-based; 0 is January)

      * @param day        The reference date's day-in-month (1-based)

      * @param dayOfWeek  The reference date's day-of-week (1-based; 1 is Sunday)

      * @param millis     The reference date's milliseconds in day, local standard time

      * @param status     Output param to filled in with a success or an error.

      * @return           The offset in milliseconds to add to GMT to get local time.

      * @stable ICU 2.0

      */

     virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,

                               uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0;

     /**

      * 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.

      *

      * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,

      * which returns both the raw and the DST offset for a given time. This method

      * is retained only for backward compatibility.

      *

      * @param era the era of the given date.

      * @param year the year in the given date.

      * @param month the month in the given date.

      * Month is 0-based. e.g., 0 for January.

      * @param day the day-in-month of the given date.

      * @param dayOfWeek the day-of-week of the given date.

      * @param milliseconds the millis in day in <em>standard</em> local time.

      * @param monthLength the length of the given month in days.

      * @param status     Output param to filled in with a success or an error.

      * @return the offset to add *to* GMT to get local time.

      * @stable ICU 2.0

      */

     virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,

                            uint8_t dayOfWeek, int32_t milliseconds,

                            int32_t monthLength, UErrorCode& status) const = 0;

     /**

      * 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().

      *

      * @param 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'.

      * @param local if true, `date' is local wall time; otherwise it

      * is in GMT time.

      * @param rawOffset output parameter to receive the raw offset, that

      * is, the offset not including DST adjustments

      * @param dstOffset output parameter to receive the DST offset,

      * that is, the offset to be added to `rawOffset' to obtain the

      * total offset between local and GMT time. If DST is not in

      * effect, this value is zero; otherwise it is a positive value,

      * typically one hour.

      * @param ec input-output error code

      *

      * @stable ICU 2.8

      */

     virtual void getOffset(UDate date, UBool local, int32_t& rawOffset,

                            int32_t& dstOffset, UErrorCode& ec) const;

     /**

      * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add

      * to GMT to get local time, before taking daylight savings time into account).

      *

      * @param offsetMillis  The new raw GMT offset for this time zone.

      * @stable ICU 2.0

      */

     virtual void setRawOffset(int32_t offsetMillis) = 0;

     /**

      * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add

      * to GMT to get local time, before taking daylight savings time into account).

      *

      * @return   The TimeZone's raw GMT offset.

      * @stable ICU 2.0

      */

     virtual int32_t getRawOffset(void) const = 0;

     /**

      * Fills in "ID" with the TimeZone's ID.

      *

      * @param ID  Receives this TimeZone's ID.

      * @return    A reference to 'ID'

      * @stable ICU 2.0

      */

     UnicodeString& getID(UnicodeString& ID) const;

     /**

      * Sets the TimeZone's ID to the specified value.  This doesn't affect any other

      * fields (for example, if you say<

      * blockquote><pre>

      * .     TimeZone* foo = TimeZone::createTimeZone("America/New_York");

      * .     foo.setID("America/Los_Angeles");

      * </pre>\htmlonly</blockquote>\endhtmlonly

      * the time zone's GMT offset and daylight-savings rules don't change to those for

      * Los Angeles.  They're still those for New York.  Only the ID has changed.)

      *

      * @param ID  The new time zone ID.

      * @stable ICU 2.0

      */

     void setID(const UnicodeString& ID);

     /**

      * Enum for use with getDisplayName

      * @stable ICU 2.4

      */

     enum EDisplayType {

         /**

          * Selector for short display name

          * @stable ICU 2.4

          */

         SHORT = 1,

         /**

          * Selector for long display name

          * @stable ICU 2.4

          */

         LONG,

         /**

          * Selector for short generic display name

          * @stable ICU 4.4

          */

         SHORT_GENERIC,

         /**

          * Selector for long generic display name

          * @stable ICU 4.4

          */

         LONG_GENERIC,

         /**

          * Selector for short display name derived

          * from time zone offset

          * @stable ICU 4.4

          */

         SHORT_GMT,

         /**

          * Selector for long display name derived

          * from time zone offset

          * @stable ICU 4.4

          */

         LONG_GMT,

         /**

          * Selector for short display name derived

          * from the time zone's fallback name

          * @stable ICU 4.4

          */

         SHORT_COMMONLY_USED,

         /**

          * Selector for long display name derived

          * from the time zone's fallback name

          * @stable ICU 4.4

          */

         GENERIC_LOCATION

     };

     /**

      * Returns a name of this time zone suitable for presentation to the user

      * in the default locale.

      * This method returns the long name, not including daylight savings.

      * If the display name is not available for the locale,

      * then this method returns a string in the format

      * <code>GMT[+-]hh:mm</code>.

      * @param result the human-readable name of this time zone in the default locale.

      * @return       A reference to 'result'.

      * @stable ICU 2.0

      */

     UnicodeString& getDisplayName(UnicodeString& result) const;

     /**

      * 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,

      * then this method returns a string in the format

      * <code>GMT[+-]hh:mm</code>.

      * @param locale the locale in which to supply the display name.

      * @param result the human-readable name of this time zone in the given locale

      *               or in the default locale if the given locale is not recognized.

      * @return       A reference to 'result'.

      * @stable ICU 2.0

      */

     UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const;

     /**

      * Returns a name of this time zone suitable for presentation to the user

      * in the default locale.

      * If the display name is not available for the locale,

      * then this method returns a string in the format

      * <code>GMT[+-]hh:mm</code>.

      * @param daylight if true, return the daylight savings name.

      * @param style

      * @param result the human-readable name of this time zone in the default locale.

      * @return       A reference to 'result'.

      * @stable ICU 2.0

      */

     UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const;

     /**

      * 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 format

      * <code>GMT[+-]hh:mm</code>.

      * @param daylight if true, return the daylight savings name.

      * @param style

      * @param locale the locale in which to supply the display name.

      * @param result the human-readable name of this time zone in the given locale

      *               or in the default locale if the given locale is not recognized.

      * @return       A refence to 'result'.

      * @stable ICU 2.0

      */

     UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const;

     /**

      * Queries if this time zone uses daylight savings time.

      * @return true if this time zone uses daylight savings time,

      * false, otherwise.

      * <p><strong>Note:</strong>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 <code>FALSE</code> for such case.

      * The default implementation of this method returns <code>TRUE</code>

      * when the time zone uses daylight savings time in the current

      * (Gregorian) calendar year.

      * <p>In Java 7, <code>observesDaylightTime()</code> was added in

      * addition to <code>useDaylightTime()</code>. In Java, <code>useDaylightTime()</code>

      * only checks if daylight saving time is observed by the last known

      * rule. This specification might not be what most users would expect

      * if daylight saving time is currently observed, but not scheduled

      * in future. In this case, Java's <code>userDaylightTime()</code> returns

      * <code>false</code>. To resolve the issue, Java 7 added <code>observesDaylightTime()</code>,

      * which takes the current rule into account. The method <code>observesDaylightTime()</code>

      * was added in ICU4J for supporting API signature compatibility with JDK.

      * In general, ICU4C also provides JDK compatible methods, but the current

      * implementation <code>userDaylightTime()</code> serves the purpose

      * (takes the current rule into account), <code>observesDaylightTime()</code>

      * is not added in ICU4C. In addition to <code>useDaylightTime()</code>, ICU4C

      * <code>BasicTimeZone</code> class (Note that <code>TimeZone::createTimeZone(const UnicodeString &ID)</code>

      * always returns a <code>BasicTimeZone</code>) provides a series of methods allowing

      * historic and future time zone rule iteration, so you can check if daylight saving

      * time is observed or not within a given period.

      * 

      * @stable ICU 2.0

      */

     virtual UBool useDaylightTime(void) const = 0;

     /**

      * Queries if the given date is in daylight savings time in

      * this time zone.

      * This method is wasteful since it creates a new GregorianCalendar and

      * deletes it each time it is called. This is a deprecated method

      * and provided only for Java compatibility.

      *

      * @param date the given UDate.

      * @param status Output param filled in with success/error code.

      * @return true if the given date is in daylight savings time,

      * false, otherwise.

      * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead.

      */

     virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0;

     /**

      * 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.

      * @param other the <code>TimeZone</code> object to be compared with

      * @return true if the given zone is the same as this one,

      * with the possible exception of the ID

      * @stable ICU 2.0

      */

     virtual UBool hasSameRules(const TimeZone& other) const;

     /**

      * Clones TimeZone objects polymorphically. Clients are responsible for deleting

      * the TimeZone object cloned.

      *

      * @return   A new copy of this TimeZone object.

      * @stable ICU 2.0

      */

     virtual TimeZone* clone(void) const = 0;

     /**

      * Return the class ID for this class.  This is useful only for

      * comparing to a return value from getDynamicClassID().

      * @return The class ID for all objects of this class.

      * @stable ICU 2.0

      */

     static UClassID U_EXPORT2 getStaticClassID(void);

     /**

      * Returns a unique class ID POLYMORPHICALLY. This method is to

      * implement a simple version of RTTI, since not all C++ compilers support genuine

      * RTTI. Polymorphic operator==() and clone() methods call this method.

      * <P>

      * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION

      *  macro from uobject.h in their implementation to provide correct RTTI information.

      * @return   The class ID for this object. All objects of a given class have the

      *           same class ID. Objects of other classes have different class IDs.

      * @stable ICU 2.0

      */

     virtual UClassID getDynamicClassID(void) const = 0;

     /**

      * Returns the amount of time to be added to local standard time

      * to get local wall clock time.

      * <p>

      * The default implementation always returns 3600000 milliseconds

      * (i.e., one hour) if this time zone observes Daylight Saving

      * Time. Otherwise, 0 (zero) is returned.

      * <p>

      * If an underlying TimeZone implementation subclass supports

      * historical Daylight Saving Time changes, this method returns

      * the known latest daylight saving value.

      *

      * @return the amount of saving time in milliseconds

      * @stable ICU 3.6

      */

     virtual int32_t getDSTSavings() const;

     /**

      * Gets 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).

      * 

      * @param id            The system time zone ID.

      * @param region        Output buffer for receiving the region code.

      * @param capacity      The size of the output buffer.

      * @param status        Receives the status.  When the given time zone ID

      *                      is not a known system time zone ID,

      *                      U_ILLEGAL_ARGUMENT_ERROR is set.

      * @return The length of the output region code.

      * @stable ICU 4.8 

      */ 

     static int32_t U_EXPORT2 getRegion(const UnicodeString& id, 

         char *region, int32_t capacity, UErrorCode& status); 

 protected:

     /**

      * Default constructor.  ID is initialized to the empty string.

      * @stable ICU 2.0

      */

     TimeZone();

     /**

      * Construct a TimeZone with a given ID.

      * @param id a system time zone ID

      * @stable ICU 2.0

      */

     TimeZone(const UnicodeString &id);

     /**

      * Copy constructor.

      * @param source the object to be copied.

      * @stable ICU 2.0

      */

     TimeZone(const TimeZone& source);

     /**

      * Default assignment operator.

      * @param right the object to be copied.

      * @stable ICU 2.0

      */

     TimeZone& operator=(const TimeZone& right);

 #ifndef U_HIDE_INTERNAL_API

     /**

      * Utility function. For internally loading rule data.

      * @param top Top resource bundle for tz data

      * @param ruleid ID of rule to load

      * @param oldbundle Old bundle to reuse or NULL

      * @param status Status parameter

      * @return either a new bundle or *oldbundle

      * @internal

      */

     static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status);

 #endif  /* U_HIDE_INTERNAL_API */

 private:

     friend class ZoneMeta;

     static TimeZone*        createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string.

     /**

      * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata,

      * returns the pointer to the ID resource. This method is exposed through ZoneMeta class

      * for ICU internal implementation and useful for building hashtable using a time zone

      * ID as a key.

      * @param id zone id string

      * @return the pointer of the ID resource, or NULL.

      */

     static const UChar* findID(const UnicodeString& id);

     /**

      * Resolve a link in Olson tzdata.  When the given id is known and it's not a link,

      * the id itself is returned.  When the given id is known and it is a link, then

      * dereferenced zone id is returned.  When the given id is unknown, then it returns

      * NULL.

      * @param id zone id string

      * @return the dereferenced zone or NULL

      */

     static const UChar* dereferOlsonLink(const UnicodeString& id);

     /**

      * Returns the region code associated with the given zone,

      * or NULL if the zone is not known.

      * @param id zone id string

      * @return the region associated with the given zone

      */

     static const UChar* getRegion(const UnicodeString& id);

   public:

 #ifndef U_HIDE_INTERNAL_API

     /**

      * Returns the region code associated with the given zone,

      * or NULL if the zone is not known.

      * @param id zone id string

      * @param status Status parameter

      * @return the region associated with the given zone

      * @internal

      */

     static const UChar* getRegion(const UnicodeString& id, UErrorCode& status);

 #endif  /* U_HIDE_INTERNAL_API */

   private:

     /**

      * Parses the given custom time zone identifier

      * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or

      * GMT[+-]hh.

      * @param sign Receves parsed sign, 1 for positive, -1 for negative.

      * @param hour Receives parsed hour field

      * @param minute Receives parsed minute field

      * @param second Receives parsed second field

      * @return Returns TRUE when the given custom id is valid.

      */

     static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour,

         int32_t& minute, int32_t& second);

     /**

      * Parse a custom time zone identifier and return the normalized

      * custom time zone identifier for the given custom id string.

      * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or

      * GMT[+-]hh.

      * @param normalized Receives the normalized custom ID

      * @param status Receives the status.  When the input ID string is invalid,

      * U_ILLEGAL_ARGUMENT_ERROR is set.

      * @return The normalized custom id string.

     */

     static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized,

         UErrorCode& status);

     /**

      * Returns the normalized custome time zone ID for the given offset fields.

      * @param hour offset hours

      * @param min offset minutes

      * @param sec offset seconds

      * @param negative sign of the offset, TRUE for negative offset.

      * @param id Receves the format result (normalized custom ID)

      * @return The reference to id

      */

     static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec,

         UBool negative, UnicodeString& id);

     UnicodeString           fID;    // this time zone's ID

     friend class TZEnumeration;

 };

 // -------------------------------------

 inline UnicodeString&

 TimeZone::getID(UnicodeString& ID) const

 {

     ID = fID;

     return ID;

 }

 // -------------------------------------

 inline void

 TimeZone::setID(const UnicodeString& ID)

 {

     fID = ID;

 }

 U_NAMESPACE_END

 #endif /* #if !UCONFIG_NO_FORMATTING */

 #endif //_TIMEZONE

 //eof