* Typically, you get a {@code TimeZone} using {@code getDefault} * which creates a {@code TimeZone} based on the time zone where the program * is running. For example, for a program running in Japan, {@code getDefault} * creates a {@code TimeZone} object based on Japanese Standard Time. * *
* You can also get a {@code TimeZone} using {@code getTimeZone} * along with a time zone ID. For instance, the time zone ID for the * U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a * U.S. Pacific Time {@code TimeZone} object with: *
* TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
* * * Hours must be between 0 to 23 and Minutes must be * between 00 to 59. For example, "GMT+10" and "GMT+0010" mean ten * hours and ten minutes ahead of GMT, respectively. ** CustomID: * {@code GMT} Sign Hours {@code :} Minutes * {@code GMT} Sign Hours Minutes * {@code GMT} Sign Hours * Sign: one of * {@code + -} * Hours: * Digit * Digit Digit * Minutes: * Digit Digit * Digit: one of * {@code 0 1 2 3 4 5 6 7 8 9} *
* 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"} * is used. *
* When creating a {@code TimeZone}, the specified custom time * zone ID is normalized in the following syntax: *
* For example, TimeZone.getTimeZone("GMT-8").getID() returns "GMT-08:00". * ** NormalizedCustomID: * {@code GMT} Sign TwoDigitHours {@code :} Minutes * Sign: one of * {@code + -} * TwoDigitHours: * Digit Digit * Minutes: * Digit Digit * Digit: one of * {@code 0 1 2 3 4 5 6 7 8 9} *
* This method returns a historically correct offset if an * underlying {@code TimeZone} 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 standard * 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. *
* 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 offsets 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. *
* If an underlying {@code TimeZone} implementation subclass * supports historical GMT offset changes, the specified GMT * offset is set as the latest GMT offset and the difference from * the known latest GMT offset value is used to adjust all * historical GMT offset values. * * @param offsetMillis the given base time zone offset to GMT. */ public abstract 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 raw * offset. *
* If an underlying {@code TimeZone} implementation subclass * supports historical GMT offset changes, the method returns the * raw offset value of the current date. In Honolulu, for example, * its raw offset changed from GMT-10:30 to GMT-10:00 in 1947, and * this method always returns -36000000 milliseconds (i.e., -10 * hours). * * @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. * *
This method is equivalent to: *
* getDisplayName(false, {@link #LONG},
* Locale.getDefault({@link Locale.Category#DISPLAY}))
* This method is equivalent to: *
* getDisplayName(false, {@link #LONG}, locale)
* This method is equivalent to: *
* getDisplayName(daylight, style,
* Locale.getDefault({@link Locale.Category#DISPLAY}))
* 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); } // END Android-added: utility method to format an offset as a GMT offset string. /** * Returns the amount of time to be added to local standard time * to get local wall clock time. * *
The default implementation returns 3600000 milliseconds * (i.e., one hour) if a call to {@link #useDaylightTime()} * returns {@code true}. Otherwise, 0 (zero) is returned. * *
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. * *
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. * *
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. * *
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.
*/
public abstract boolean inDaylightTime(Date date);
/**
* Gets the {@code TimeZone} for the given ID.
*
* @param id the ID for a TimeZone, either an abbreviation
* such as "PST", a full name such as "America/Los_Angeles", or a custom
* ID such as "GMT-8:00". Note that the support of abbreviations is
* for JDK 1.1.x compatibility only and full names should be used.
*
* @return the specified {@code TimeZone}, or the GMT zone if the given ID
* cannot be understood.
*/
// Android-changed: param s/ID/id; use ZoneInfoDb instead of ZoneInfo class.
public static synchronized 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();
}
}
// In the database?
ZoneInfoData zoneInfoData = ZoneInfoDb.getInstance().makeZoneInfoData(id);
TimeZone zone = zoneInfoData == null ? null : ZoneInfo.createZoneInfo(zoneInfoData);
// 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();
}
/**
* Gets the {@code TimeZone} for the given {@code zoneId}.
*
* @param zoneId a {@link ZoneId} from which the time zone ID is obtained
* @return the specified {@code TimeZone}, or the GMT zone if the given ID
* cannot be understood.
* @throws NullPointerException if {@code zoneId} is {@code null}
* @since 1.8
*/
public static TimeZone getTimeZone(ZoneId zoneId) {
String tzid = zoneId.getId(); // throws an NPE if null
char c = tzid.charAt(0);
if (c == '+' || c == '-') {
tzid = "GMT" + tzid;
} else if (c == 'Z' && tzid.length() == 1) {
tzid = "UTC";
}
return getTimeZone(tzid);
}
/**
* Converts this {@code TimeZone} object to a {@code ZoneId}.
*
* @return a {@code ZoneId} representing the same time zone as this
* {@code TimeZone}
* @since 1.8
*/
public ZoneId toZoneId() {
// Android-changed: don't support "old mapping"
return ZoneId.of(getID(), ZoneId.SHORT_IDS);
}
/**
* 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);
}
/**
* 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 synchronized String[] getAvailableIDs(int rawOffset) {
return ZoneInfoDb.getInstance().getAvailableIDs(rawOffset);
}
/**
* Gets all the available IDs supported.
* @return an array of IDs.
*/
public static synchronized String[] getAvailableIDs() {
return ZoneInfoDb.getInstance().getAvailableIDs();
}
/**
* Gets the platform defined TimeZone ID.
**/
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")
*/
private static native String getSystemGMTOffsetID();
/**
* Gets the default TimeZone for this host.
* The source of the default TimeZone
* may vary with implementation.
* @return a default TimeZone.
* @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) {
Supplier