/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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/*
* (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.util;
import com.google.j2objc.util.NativeTimeZone;
import java.io.IOException;
import java.io.Serializable;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.lang.ref.SoftReference;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.concurrent.ConcurrentHashMap;
import libcore.icu.TimeZoneNames;
import libcore.io.IoUtils;
/**
* <code>TimeZone</code> represents a time zone offset, and also figures out daylight
* savings.
*
* <p>
* Typically, you get a <code>TimeZone</code> using <code>getDefault</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>getDefault</code>
* creates a <code>TimeZone</code> object based on Japanese Standard Time.
*
* <p>
* You can also get a <code>TimeZone</code> using <code>getTimeZone</code>
* 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 <code>TimeZone</code> object with:
* <blockquote><pre>
* TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
* </pre></blockquote>
* You can use the <code>getAvailableIDs</code> method to iterate through
* all the supported time zone IDs. 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 a custom time zone ID can be specified to
* produce a TimeZone. The syntax of a custom time zone ID is:
*
* <blockquote><pre>
* <a name="CustomID"><i>CustomID:</i></a>
* <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i>
* <code>GMT</code> <i>Sign</i> <i>Hours</i> <i>Minutes</i>
* <code>GMT</code> <i>Sign</i> <i>Hours</i>
* <i>Sign:</i> one of
* <code>+ -</code>
* <i>Hours:</i>
* <i>Digit</i>
* <i>Digit</i> <i>Digit</i>
* <i>Minutes:</i>
* <i>Digit</i> <i>Digit</i>
* <i>Digit:</i> one of
* <code>0 1 2 3 4 5 6 7 8 9</code>
* </pre></blockquote>
*
* <i>Hours</i> must be between 0 to 23 and <i>Minutes</i> must be
* between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten
* hours and ten minutes ahead of GMT, respectively.
* <p>
* 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, <code>"GMT"</code>
* is used.
* <p>
* When creating a <code>TimeZone</code>, the specified custom time
* zone ID is normalized in the following syntax:
* <blockquote><pre>
* <a name="NormalizedCustomID"><i>NormalizedCustomID:</i></a>
* <code>GMT</code> <i>Sign</i> <i>TwoDigitHours</i> <code>:</code> <i>Minutes</i>
* <i>Sign:</i> one of
* <code>+ -</code>
* <i>TwoDigitHours:</i>
* <i>Digit</i> <i>Digit</i>
* <i>Minutes:</i>
* <i>Digit</i> <i>Digit</i>
* <i>Digit:</i> one of
* <code>0 1 2 3 4 5 6 7 8 9</code>
* </pre></blockquote>
* For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00".
*
* <h4>Three-letter time zone IDs</h4>
*
* For compatibility with JDK 1.1.x, some other three-letter time zone IDs
* (such as "PST", "CTT", "AST") are also supported. However, <strong>their
* use is deprecated</strong> 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 Calendar
* @see GregorianCalendar
* @see SimpleTimeZone
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
* @since JDK1.1
*/
abstract public class TimeZone implements Serializable, Cloneable {
/**
* Sole constructor. (For invocation by subclass constructors, typically
* implicit.)
*/
public TimeZone() {
}
/**
* A style specifier for <code>getDisplayName()</code> indicating
* a short name, such as "PST."
* @see #LONG
* @since 1.2
*/
public static final int SHORT = 0;
/**
* A style specifier for <code>getDisplayName()</code> indicating
* a long name, such as "Pacific Standard Time."
* @see #SHORT
* @since 1.2
*/
public static final int LONG = 1;
// Use a preload holder to allow compile-time initialization of TimeZone and dependents.
private static class NoImagePreloadHolder {
public static final Pattern CUSTOM_ZONE_ID_PATTERN = Pattern.compile("^GMT[-+](\\d{1,2})(:?(\\d\\d))?$");
}
// Proclaim serialization compatibility with JDK 1.1
static final long serialVersionUID = 3581463369166924961L;
private static final TimeZone GMT = new SimpleTimeZone(0, "GMT");
private static final TimeZone UTC = new SimpleTimeZone(0, "UTC");
/**
* 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>
* This method returns a historically correct offset if an
* underlying <code>TimeZone</code> implementation subclass
* supports historical Daylight Saving Time schedule and GMT
* offset changes.
*
* @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 milliseconds in day in <em>standard</em>
* local time.
*
* @return the offset in milliseconds to add to GMT to get local time.
*
* @see Calendar#ZONE_OFFSET
* @see Calendar#DST_OFFSET
*/
public abstract int getOffset(int era, int year, int month, int day,
int dayOfWeek, int milliseconds);
/**
* 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.
* <p>
* This method returns a historically correct offset value if an
* underlying TimeZone implementation subclass supports historical
* Daylight Saving Time schedule and GMT offset changes.
*
* @param date the date represented in milliseconds since January 1, 1970 00:00:00 GMT
* @return the amount of time in milliseconds to add to UTC to get local time.
*
* @see Calendar#ZONE_OFFSET
* @see Calendar#DST_OFFSET
* @since 1.4
*/
public int getOffset(long date) {
if (inDaylightTime(new Date(date))) {
return getRawOffset() + getDSTSavings();
}
return getRawOffset();
}
/**
* Gets the raw GMT offset and the amount of daylight saving of this
* time zone at the given time.
* @param date the milliseconds (since January 1, 1970,
* 00:00:00.000 GMT) at which the time zone offset and daylight
* saving amount are found
* @param offset an array of int where the raw GMT offset
* (offset[0]) and daylight saving amount (offset[1]) are stored,
* or null if those values are not needed. The method assumes that
* the length of the given array is two or larger.
* @return the total amount of the raw GMT offset and daylight
* saving at the specified date.
*
* @see Calendar#ZONE_OFFSET
* @see Calendar#DST_OFFSET
*/
int getOffsets(long date, int[] offsets) {
int rawoffset = getRawOffset();
int dstoffset = 0;
if (inDaylightTime(new Date(date))) {
dstoffset = getDSTSavings();
}
if (offsets != null) {
offsets[0] = rawoffset;
offsets[1] = dstoffset;
}
return rawoffset + dstoffset;
}
/**
* Sets the base time zone offset to GMT.
* This is the offset to add to UTC to get local time.
* <p>
* If an underlying <code>TimeZone</code> 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.
*
* @param offsetMillis the given base time zone offset to GMT.
*/
abstract public void setRawOffset(int offsetMillis);
/**
* 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 <I>raw
* offset</I>.
* <p>
* If an underlying <code>TimeZone</code> 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).
*
* @return the amount of raw offset time in milliseconds to add to UTC.
* @see Calendar#ZONE_OFFSET
*/
public abstract int getRawOffset();
/**
* Gets the ID of this time zone.
* @return the ID of this time zone.
*/
public String getID()
{
return ID;
}
/**
* Sets the time zone ID. This does not change any other data in
* the time zone object.
* @param ID the new time zone ID.
*/
public void setID(String ID)
{
if (ID == null) {
throw new NullPointerException();
}
this.ID = ID;
}
/**
* Returns a long standard time name of this {@code TimeZone} suitable for
* presentation to the user in the default locale.
*
* <p>This method is equivalent to:
* <pre><blockquote>
* getDisplayName(false, {@link #LONG},
* Locale.getDefault({@link Locale.Category#DISPLAY}))
* </blockquote></pre>
*
* @return the human-readable name of this time zone in the default locale.
* @since 1.2
* @see #getDisplayName(boolean, int, Locale)
* @see Locale#getDefault(Locale.Category)
* @see Locale.Category
*/
public final String getDisplayName() {
return getDisplayName(false, LONG,
Locale.getDefault(Locale.Category.DISPLAY));
}
/**
* Returns a long standard time name of this {@code TimeZone} suitable for
* presentation to the user in the specified {@code locale}.
*
* <p>This method is equivalent to:
* <pre><blockquote>
* getDisplayName(false, {@link #LONG}, locale)
* </blockquote></pre>
*
* @param locale the locale in which to supply the display name.
* @return the human-readable name of this time zone in the given locale.
* @exception NullPointerException if {@code locale} is {@code null}.
* @since 1.2
* @see #getDisplayName(boolean, int, Locale)
*/
public final String getDisplayName(Locale locale) {
return getDisplayName(false, LONG, locale);
}
/**
* Returns a name in the specified {@code style} of this {@code TimeZone}
* suitable for presentation to the user in the default locale. If the
* specified {@code daylight} is {@code true}, a Daylight Saving Time name
* is returned (even if this {@code TimeZone} doesn't observe Daylight Saving
* Time). Otherwise, a Standard Time name is returned.
*
* <p>This method is equivalent to:
* <pre><blockquote>
* getDisplayName(daylight, style,
* Locale.getDefault({@link Locale.Category#DISPLAY}))
* </blockquote></pre>
*
* @param daylight {@code true} specifying a Daylight Saving Time name, or
* {@code false} specifying a Standard Time name
* @param style either {@link #LONG} or {@link #SHORT}
* @return the human-readable name of this time zone in the default locale.
* @exception IllegalArgumentException if {@code style} is invalid.
* @since 1.2
* @see #getDisplayName(boolean, int, Locale)
* @see Locale#getDefault(Locale.Category)
* @see Locale.Category
* @see java.text.DateFormatSymbols#getZoneStrings()
*/
public final String getDisplayName(boolean daylight, int style) {
return getDisplayName(daylight, style,
Locale.getDefault(Locale.Category.DISPLAY));
}
/**
* Returns the {@link #SHORT short} or {@link #LONG long} name of this time
* zone with either standard or daylight time, as written in {@code locale}.
* If the name is not available, the result is in the format
* {@code GMT[+-]hh:mm}.
*
* @param daylightTime true for daylight time, false for standard time.
* @param style either {@link TimeZone#LONG} or {@link TimeZone#SHORT}.
* @param locale the display locale.
*/
public String getDisplayName(boolean daylightTime, int style, Locale locale) {
if (style != SHORT && style != LONG) {
throw new IllegalArgumentException("Bad style: " + style);
}
String[][] zoneStrings = TimeZoneNames.getZoneStrings(locale);
String result = TimeZoneNames.getDisplayName(zoneStrings, getID(), daylightTime, style);
if (result != null) {
return result;
}
// If we get here, it's because icu4c has nothing for us. Most commonly, this is in the
// case of short names. For Pacific/Fiji, for example, icu4c has nothing better to offer
// than "GMT+12:00". Why do we re-do this work ourselves? Because we have up-to-date
// time zone transition data, which icu4c _doesn't_ use --- it uses its own baked-in copy,
// which only gets updated when we update icu4c. http://b/7955614 and http://b/8026776.
// TODO: should we generate these once, in TimeZoneNames.getDisplayName? Revisit when we
// upgrade to icu4c 50 and rewrite the underlying native code. See also the
// "element[j] != null" check in SimpleDateFormat.parseTimeZone, and the extra work in
// DateFormatSymbols.getZoneStrings.
int offsetMillis = getRawOffset();
if (daylightTime) {
offsetMillis += getDSTSavings();
}
return createGmtOffsetString(true /* includeGmt */, true /* includeMinuteSeparator */,
offsetMillis);
}
/**
* Returns a string representation of an offset from UTC.
*
* <p>The format is "[GMT](+|-)HH[:]MM". The output is not localized.
*
* @param includeGmt true to include "GMT", false to exclude
* @param includeMinuteSeparator true to include the separator between hours and minutes, false
* to exclude.
* @param offsetMillis the offset from UTC
*
* @hide used internally by SimpleDateFormat
*/
public static String createGmtOffsetString(boolean includeGmt,
boolean includeMinuteSeparator, int offsetMillis) {
int offsetMinutes = offsetMillis / 60000;
char sign = '+';
if (offsetMinutes < 0) {
sign = '-';
offsetMinutes = -offsetMinutes;
}
StringBuilder builder = new StringBuilder(9);
if (includeGmt) {
builder.append("GMT");
}
builder.append(sign);
appendNumber(builder, 2, offsetMinutes / 60);
if (includeMinuteSeparator) {
builder.append(':');
}
appendNumber(builder, 2, offsetMinutes % 60);
return builder.toString();
}
private static void appendNumber(StringBuilder builder, int count, int value) {
String string = Integer.toString(value);
for (int i = 0; i < count - string.length(); i++) {
builder.append('0');
}
builder.append(string);
}
/**
* Returns the amount of time to be added to local standard time
* to get local wall clock time.
*
* <p>The default implementation returns 3600000 milliseconds
* (i.e., one hour) if a call to {@link #useDaylightTime()}
* returns {@code true}. Otherwise, 0 (zero) is returned.
*
* <p>If an underlying {@code 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.
*
* <p>If the amount of saving time at any given time stamp is
* required, construct a {@link Calendar} with this {@code
* TimeZone} and the time stamp, and call {@link Calendar#get(int)
* Calendar.get}{@code (}{@link Calendar#DST_OFFSET}{@code )}.
*
* @return the amount of saving time in milliseconds
* @since 1.4
* @see #inDaylightTime(Date)
* @see #getOffset(long)
* @see #getOffset(int,int,int,int,int,int)
* @see Calendar#ZONE_OFFSET
*/
public int getDSTSavings() {
if (useDaylightTime()) {
return 3600000;
}
return 0;
}
/**
* Queries if this {@code TimeZone} uses Daylight Saving Time.
*
* <p>If an underlying {@code 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 {@link #observesDaylightTime()}
* if the current rule should also be taken into account.
*
* @return {@code true} if this {@code TimeZone} uses Daylight Saving Time,
* {@code false}, otherwise.
* @see #inDaylightTime(Date)
* @see Calendar#DST_OFFSET
*/
public abstract boolean useDaylightTime();
/**
* Returns {@code true} if this {@code TimeZone} is currently in
* Daylight Saving Time, or if a transition from Standard Time to
* Daylight Saving Time occurs at any future time.
*
* <p>The default implementation returns {@code true} if
* {@code useDaylightTime()} or {@code inDaylightTime(new Date())}
* returns {@code true}.
*
* @return {@code true} if this {@code TimeZone} is currently in
* Daylight Saving Time, or if a transition from Standard Time to
* Daylight Saving Time occurs at any future time; {@code false}
* otherwise.
* @since 1.7
* @see #useDaylightTime()
* @see #inDaylightTime(Date)
* @see Calendar#DST_OFFSET
*/
public boolean observesDaylightTime() {
return useDaylightTime() || inDaylightTime(new Date());
}
/**
* Queries if the given {@code date} is in Daylight Saving Time in
* this time zone.
*
* @param date the given Date.
* @return {@code true} if the given date is in Daylight Saving Time,
* {@code false}, otherwise.
*/
abstract public boolean inDaylightTime(Date date);
/**
* Gets the <code>TimeZone</code> for the given ID.
*
* @param id the ID for a <code>TimeZone</code>, 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.
*
* @return the specified <code>TimeZone</code>, or the GMT zone if the given ID
* cannot be understood.
*/
// Android changed param s/ID/id
public static TimeZone getTimeZone(String id) {
if (id == null) {
throw new NullPointerException("id == null");
}
// Special cases? These can clone an existing instance.
if (id.length() == 3) {
if (id.equals("GMT")) {
return (TimeZone) GMT.clone();
}
if (id.equals("UTC")) {
return (TimeZone) UTC.clone();
}
}
// Native time zone?
TimeZone zone = NativeTimeZone.get(id);
// Custom time zone?
if (zone == null && id.length() > 3 && id.startsWith("GMT")) {
zone = getCustomTimeZone(id);
}
// We never return null; on failure we return the equivalent of "GMT".
return (zone != null) ? zone : (TimeZone) GMT.clone();
}
/**
* Returns a new SimpleTimeZone for an ID of the form "GMT[+|-]hh[[:]mm]", or null.
*/
private static TimeZone getCustomTimeZone(String id) {
Matcher m = NoImagePreloadHolder.CUSTOM_ZONE_ID_PATTERN.matcher(id);
if (!m.matches()) {
return null;
}
int hour;
int minute = 0;
try {
hour = Integer.parseInt(m.group(1));
if (m.group(3) != null) {
minute = Integer.parseInt(m.group(3));
}
} catch (NumberFormatException impossible) {
throw new AssertionError(impossible);
}
if (hour < 0 || hour > 23 || minute < 0 || minute > 59) {
return null;
}
char sign = id.charAt(3);
int raw = (hour * 3600000) + (minute * 60000);
if (sign == '-') {
raw = -raw;
}
String cleanId = String.format(Locale.ROOT, "GMT%c%02d:%02d", sign, hour, minute);
return new SimpleTimeZone(raw, cleanId);
}
/**
* J2ObjC added.
* A static class is used for lazy-initialization of available time zone IDs.
*/
static class AvailableIDsGetter {
static final String[] IDS = getAllIds();
static String[] getAllIds() {
String[] allIds = NativeTimeZone.getAvailableNativeTimeZoneNames();
for (String id : allIds) {
if (id.equals("UTC")) {
return allIds;
}
}
int len = allIds.length;
String[] newIds = Arrays.copyOf(allIds, len + 1);
newIds[len] = "UTC";
return newIds;
}
}
/**
* Gets the available IDs according to the given time zone offset in milliseconds.
*
* @param rawOffset the given time zone GMT offset in milliseconds.
* @return 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 #getRawOffset()
*/
public static String[] getAvailableIDs(int rawOffset) {
List<String> ids = new ArrayList<>();
for (String id : getAvailableIDs()) {
TimeZone tz = NativeTimeZone.get(id);
if (tz.getRawOffset() == rawOffset) {
ids.add(id);
}
}
return ids.toArray(new String[0]);
}
/**
* Gets all the available IDs supported.
* @return an array of IDs.
*/
public static String[] getAvailableIDs() {
return AvailableIDsGetter.IDS;
}
/**
* Gets the platform defined TimeZone ID.
* J2ObjC unused.
private static native String getSystemTimeZoneID(String javaHome,
String country);*/
/**
* Gets the custom time zone ID based on the GMT offset of the
* platform. (e.g., "GMT+08:00")
* J2ObjC unused.
private static native String getSystemGMTOffsetID();*/
/**
* Gets the default <code>TimeZone</code> for this host.
* The source of the default <code>TimeZone</code>
* may vary with implementation.
* @return a default <code>TimeZone</code>.
* @see #setDefault
*/
public static TimeZone getDefault() {
return (TimeZone) getDefaultRef().clone();
}
/**
* Returns the reference to the default TimeZone object. This
* method doesn't create a clone.
*/
static synchronized TimeZone getDefaultRef() {
if (defaultTimeZone == null) {
defaultTimeZone = NativeTimeZone.getDefaultNativeTimeZone();
}
if (defaultTimeZone == null) {
defaultTimeZone = GMT;
}
return defaultTimeZone;
}
/**
* Sets the <code>TimeZone</code> that is
* returned by the <code>getDefault</code> method. If <code>zone</code>
* is null, reset the default to the value it had originally when the
* VM first started.
* @param timeZone the new default time zone
* @see #getDefault
*/
// Android changed s/zone/timeZone
public synchronized static void setDefault(TimeZone timeZone) {
defaultTimeZone = timeZone != null ? (TimeZone) timeZone.clone() : null;
}
/**
* 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.
* @param other the <code>TimeZone</code> object to be compared with
* @return true if the other zone is not null and is the same as this one,
* with the possible exception of the ID
* @since 1.2
*/
public boolean hasSameRules(TimeZone other) {
return other != null && getRawOffset() == other.getRawOffset() &&
useDaylightTime() == other.useDaylightTime();
}
/**
* Creates a copy of this <code>TimeZone</code>.
*
* @return a clone of this <code>TimeZone</code>
*/
public Object clone()
{
try {
TimeZone other = (TimeZone) super.clone();
other.ID = ID;
return other;
} catch (CloneNotSupportedException e) {
throw new InternalError();
}
}
/**
* The null constant as a TimeZone.
*/
static final TimeZone NO_TIMEZONE = null;
// =======================privates===============================
/**
* The string identifier of this <code>TimeZone</code>. This is a
* programmatic identifier used internally to look up <code>TimeZone</code>
* objects from the system table and also to map them to their localized
* display names. <code>ID</code> values are unique in the system
* table but may not be for dynamically created zones.
* @serial
*/
private String ID;
private static volatile TimeZone defaultTimeZone;
}