com.ibm.icu.util
public abstract class TimeZone extends java.lang.Object implements java.io.Serializable, java.lang.Cloneable
TimeZone
represents a time zone offset, and also figures out daylight
savings.
Typically, you get a TimeZone
using getDefault
which creates a TimeZone
based on the time zone where the program
is running. For example, for a program running in Japan, getDefault
creates a TimeZone
object based on Japanese Standard Time.
You can also get a TimeZone
using getTimeZone
along with a time zone ID. For instance, the time zone ID for the
U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a
U.S. Pacific Time TimeZone
object with:
You can useTimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
getAvailableIDs
method to iterate through
all the supported time zone IDs. You can then choose a
supported ID to get a TimeZone
.
If the time zone you want is not represented by one of the
supported IDs, then you can create a custom time zone ID with
the following syntax:
For example, you might specify GMT+14:00 as a custom time zone ID. TheGMT[+|-]hh[[:]mm]
TimeZone
that is returned
when you specify a custom time zone ID does not include
daylight savings time.
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 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 setDefaultTimeZoneType
at runtime.
Calendar
,
GregorianCalendar
,
SimpleTimeZone
,
Serialized FormModifier and Type | Field and Description |
---|---|
static int |
LONG
A style specifier for
getDisplayName() indicating
a long name, such as "Pacific Standard Time." |
static int |
SHORT
A style specifier for
getDisplayName() indicating
a short name, such as "PST." |
static int |
TIMEZONE_ICU
A time zone implementation type indicating ICU's own TimeZone used by
getTimeZone , setDefaultTimeZoneType
and getDefaultTimeZoneType . |
static int |
TIMEZONE_JDK
A time zone implementation type indicating JDK TimeZone used by
getTimeZone , setDefaultTimeZoneType
and getDefaultTimeZoneType . |
Constructor and Description |
---|
TimeZone()
Default constructor.
|
Modifier and Type | Method and Description |
---|---|
java.lang.Object |
clone()
Overrides Cloneable
|
static int |
countEquivalentIDs(java.lang.String id)
Returns the number of IDs in the equivalency group that
includes the given ID.
|
boolean |
equals(java.lang.Object obj)
Return true if obj is a TimeZone with the same class and ID as this.
|
static java.lang.String[] |
getAvailableIDs()
Return a new String array containing all system TimeZone IDs.
|
static java.lang.String[] |
getAvailableIDs(int rawOffset)
Return a new String array containing all system TimeZone IDs
with the given raw offset from GMT.
|
static java.lang.String[] |
getAvailableIDs(java.lang.String country)
Return a new String array containing all system TimeZone IDs
associated with the given country.
|
static java.lang.String |
getCanonicalID(java.lang.String id)
Returns the canonical system time zone ID or the normalized
custom time zone ID for the given time zone ID.
|
static java.lang.String |
getCanonicalID(java.lang.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 |
getDefault()
Gets the default
TimeZone for this host. |
static int |
getDefaultTimeZoneType()
Returns the default time zone type currently used.
|
java.lang.String |
getDisplayName()
Returns a name of this time zone suitable for presentation to the user
in the default locale.
|
java.lang.String |
getDisplayName(boolean daylight,
int style)
Returns a name of this time zone suitable for presentation to the user
in the default locale.
|
java.lang.String |
getDisplayName(boolean daylight,
int style,
java.util.Locale locale)
Returns a name of this time zone suitable for presentation to the user
in the specified locale.
|
java.lang.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.
|
java.lang.String |
getDisplayName(java.util.Locale locale)
Returns a name of this time zone suitable for presentation to the user
in the specified locale.
|
java.lang.String |
getDisplayName(ULocale locale)
Returns a name of this time zone suitable for presentation to the user
in the specified locale.
|
int |
getDSTSavings()
Returns the amount of time to be added to local standard time
to get local wall clock time.
|
static java.lang.String |
getEquivalentID(java.lang.String id,
int index)
Returns an ID in the equivalency group that
includes the given ID.
|
java.lang.String |
getID()
Gets the ID of this time zone.
|
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 |
getRawOffset()
Gets unmodified offset, NOT modified in case of daylight savings.
|
static TimeZone |
getTimeZone(java.lang.String ID)
Gets the
TimeZone for the given ID. |
static TimeZone |
getTimeZone(java.lang.String ID,
int type)
Gets the
TimeZone for the given ID and the timezone type. |
static java.lang.String |
getTZDataVersion()
Returns the time zone data version currently used by ICU.
|
int |
hashCode()
Return the hash code.
|
boolean |
hasSameRules(TimeZone other)
Returns true if this zone has the same rule and offset as another zone.
|
abstract boolean |
inDaylightTime(java.util.Date date)
Queries if the given date is in daylight savings time in
this time zone.
|
static void |
setDefault(TimeZone tz)
Sets the
TimeZone that is
returned by the getDefault method. |
static void |
setDefaultTimeZoneType(int type)
Sets the default time zone type used by
getTimeZone . |
void |
setID(java.lang.String ID)
Sets the time zone ID.
|
abstract void |
setRawOffset(int offsetMillis)
Sets the base time zone offset to GMT.
|
abstract boolean |
useDaylightTime()
Queries if this time zone uses daylight savings time.
|
public static final int TIMEZONE_ICU
getTimeZone
, setDefaultTimeZoneType
and getDefaultTimeZoneType
.public static final int TIMEZONE_JDK
getTimeZone
, setDefaultTimeZoneType
and getDefaultTimeZoneType
.public static final int SHORT
getDisplayName()
indicating
a short name, such as "PST."LONG
,
Constant Field Valuespublic static final int LONG
getDisplayName()
indicating
a long name, such as "Pacific Standard Time."SHORT
,
Constant Field Valuespublic TimeZone()
public abstract int getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds)
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.public int getOffset(long date)
date
- the date represented in milliseconds since January 1, 1970 00:00:00 GMTCalendar.ZONE_OFFSET
,
Calendar.DST_OFFSET
,
getOffset(long, boolean, int[])
public void getOffset(long date, boolean local, int[] offsets)
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.public abstract void setRawOffset(int offsetMillis)
offsetMillis
- the given base time zone offset to GMT.public abstract int getRawOffset()
public java.lang.String getID()
public void setID(java.lang.String ID)
ID
- the new time zone ID.public final java.lang.String getDisplayName()
public final java.lang.String getDisplayName(java.util.Locale locale)
locale
- the locale in which to supply the display name.public final java.lang.String getDisplayName(ULocale locale)
locale
- the ulocale in which to supply the display name.public final java.lang.String getDisplayName(boolean daylight, int style)
GMT[+-]hh:mm
.daylight
- if true, return the daylight savings name.style
- either LONG
or SHORT
public java.lang.String getDisplayName(boolean daylight, int style, java.util.Locale locale)
GMT[+-]hh:mm
.daylight
- if true, return the daylight savings name.style
- either LONG
or SHORT
locale
- the locale in which to supply the display name.java.lang.IllegalArgumentException
- style is invalid.public java.lang.String getDisplayName(boolean daylight, int style, ULocale locale)
GMT[+-]hh:mm
.daylight
- if true, return the daylight savings name.style
- either LONG
or SHORT
locale
- the locale in which to supply the display name.java.lang.IllegalArgumentException
- style is invalid.public int getDSTSavings()
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.
public abstract boolean useDaylightTime()
public abstract boolean inDaylightTime(java.util.Date date)
date
- the given Date.public static TimeZone getTimeZone(java.lang.String ID)
TimeZone
for the given ID.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.TimeZone
, or the GMT zone if the given ID
cannot be understood.public static TimeZone getTimeZone(java.lang.String ID, int type)
TimeZone
for the given ID and the timezone type.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
.TimeZone
, or the GMT zone if the given ID
cannot be understood.public static void setDefaultTimeZoneType(int type)
getTimeZone
.type
- time zone type, either TIMEZONE_ICU
or TIMEZONE_JDK
.public static int getDefaultTimeZoneType()
TIMEZONE_ICU
or TIMEZONE_JDK
.public static java.lang.String[] getAvailableIDs(int rawOffset)
get()
to construct the corresponding TimeZone
object.rawOffset
- the offset in milliseconds from GMTpublic static java.lang.String[] getAvailableIDs(java.lang.String country)
get()
to construct the corresponding TimeZone
object.country
- a two-letter ISO 3166 country code, or null
to return zones not associated with any countrypublic static java.lang.String[] getAvailableIDs()
get()
to construct the corresponding TimeZone
object.public static int countEquivalentIDs(java.lang.String id)
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.
id
- a system time zone IDgetEquivalentID(java.lang.String, int)
public static java.lang.String getEquivalentID(java.lang.String id, int index)
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.
id
- a system time zone IDindex
- a value from 0 to n-1, where n is the value
returned by countEquivalentIDs(id)
countEquivalentIDs(java.lang.String)
public static TimeZone getDefault()
TimeZone
for this host.
The source of the default TimeZone
may vary with implementation.TimeZone
.public static void setDefault(TimeZone tz)
TimeZone
that is
returned by the getDefault
method. If zone
is null, reset the default to the value it had originally when the
VM first started.tz
- the new default time zonepublic boolean hasSameRules(TimeZone other)
other
- the TimeZone
object to be compared withpublic java.lang.Object clone()
clone
in class java.lang.Object
public boolean equals(java.lang.Object obj)
equals
in class java.lang.Object
obj
- the object to compare againstpublic int hashCode()
hashCode
in class java.lang.Object
public static java.lang.String getTZDataVersion()
java.util.MissingResourceException
- if ICU time zone resource bundle
is missing or the version information is not available.public static java.lang.String getCanonicalID(java.lang.String id)
id
- The input time zone ID to be canonicalized.public static java.lang.String getCanonicalID(java.lang.String id, boolean[] isSystemID)
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]
Copyright (c) 2009 IBM Corporation and others.