public
abstract
class
TimeZone
extends Object
implements
Serializable,
Cloneable,
Freezable<TimeZone>
java.lang.Object | |
↳ | android.icu.util.TimeZone |
[icu enhancement] ICU's replacement for TimeZone
. Methods, fields, and other functionality specific to ICU are labeled '[icu]'.
TimeZone
represents a time zone offset, and also computes daylight
savings.
Typically, you get a TimeZone
using getDefault()
which creates a TimeZone
based on the time zone where the program
is running. For example, for a program running in Japan, getDefault
creates a TimeZone
object based on Japanese Standard Time.
You can also get a TimeZone
using getTimeZone(String)
along with a time zone ID. For instance, the time zone ID for the
U.S. Pacific Time zone is "America/Los_Angeles". So, you can get a
U.S. Pacific Time TimeZone
object with:
You can use theTimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
getAvailableIDs()
method to iterate through
all the supported time zone IDs, or getCanonicalID method to check
if a time zone ID is supported or not. You can then choose a
supported ID to get a TimeZone
.
If the time zone you want is not represented by one of the
supported IDs, then you can create a custom time zone ID with
the following syntax:
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 uses the specified
offset from GMT(=UTC) and does not observe daylight saving
time. For example, you might specify GMT+14:00 as a custom
time zone ID to create a TimeZone representing 14 hours ahead
of GMT (with no daylight saving time). In addition,
getCanonicalID
can also be used to
normalize a custom time zone ID.
For compatibility with JDK 1.1.x, some other three-letter time zone IDs (such as "PST", "CTT", "AST") are also supported. However, their use is deprecated because the same abbreviation is often used for multiple time zones (for example, "CST" could be U.S. "Central Standard Time" and "China Standard Time"), and the Java platform can then only recognize one of them.
See also:
Calendar
GregorianCalendar
Nested classes | |
---|---|
enum |
TimeZone.SystemTimeZoneType
[icu] System time zone type constants used by filtering zones in
|
Constants | |
---|---|
int |
GENERIC_LOCATION
[icu] A style specifier for |
int |
LONG
A style specifier for |
int |
LONG_GENERIC
[icu] A style specifier for |
int |
LONG_GMT
[icu] A style specifier for |
int |
SHORT
A style specifier for |
int |
SHORT_COMMONLY_USED
[icu] A style specifier for |
int |
SHORT_GENERIC
[icu] A style specifier for |
int |
SHORT_GMT
[icu] A style specifier for |
String |
UNKNOWN_ZONE_ID
[icu] The time zone ID reserved for unknown time zone. |
Fields | |
---|---|
public
static
final
TimeZone |
GMT_ZONE
[icu] The immutable GMT (=UTC) time zone. |
public
static
final
TimeZone |
UNKNOWN_ZONE
[icu] The immutable (frozen) "unknown" time zone. |
Public constructors | |
---|---|
TimeZone()
Default constructor. |
Public methods | |
---|---|
Object
|
clone()
Overrides clone. |
TimeZone
|
cloneAsThawed()
Provides for the clone operation. |
static
int
|
countEquivalentIDs(String id)
[icu] Returns the number of IDs in the equivalency group that includes the given ID. |
boolean
|
equals(Object obj)
Overrides equals. |
TimeZone
|
freeze()
Freezes the object. |
static
String[]
|
getAvailableIDs()
Return a new String array containing all system TimeZone IDs. |
static
String[]
|
getAvailableIDs(int rawOffset)
Return a new String array containing all system TimeZone IDs with the given raw offset from GMT. |
static
Set<String>
|
getAvailableIDs(TimeZone.SystemTimeZoneType zoneType, String region, Integer rawOffset)
[icu] Returns a set of time zone ID strings with the given filter conditions. |
static
String[]
|
getAvailableIDs(String country)
Return a new String array containing all system TimeZone IDs associated with the given country. |
static
String
|
getCanonicalID(String id)
[icu] Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID. |
static
String
|
getCanonicalID(String id, boolean[] isSystemID)
[icu] Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID. |
int
|
getDSTSavings()
Returns the amount of time to be added to local standard time to get local wall clock time. |
static
TimeZone
|
getDefault()
Gets the default |
String
|
getDisplayName(boolean daylight, int style, Locale locale)
Returns a name of this time zone suitable for presentation to the user in the specified locale. |
final
String
|
getDisplayName()
Returns a name of this time zone suitable for presentation to the user
in the default |
final
String
|
getDisplayName(ULocale locale)
Returns a name of this time zone suitable for presentation to the user in the specified locale. |
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. |
final
String
|
getDisplayName(Locale locale)
Returns a name of this time zone suitable for presentation to the user in the specified locale. |
final
String
|
getDisplayName(boolean daylight, int style)
Returns a name of this time zone suitable for presentation to the user
in the default |
static
String
|
getEquivalentID(String id, int index)
Returns an ID in the equivalency group that includes the given ID. |
static
TimeZone
|
getFrozenTimeZone(String ID)
Gets the |
String
|
getID()
Gets the ID of this time zone. |
static
String
|
getIDForWindowsID(String winid, String region)
[icu] Converts a Windows time zone ID to an equivalent system time zone ID for a region. |
void
|
getOffset(long date, boolean local, int[] offsets)
Returns the time zone raw and GMT offset for the given moment in time. |
int
|
getOffset(long date)
Returns the offset of this time zone from UTC at the specified date. |
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. |
abstract
int
|
getRawOffset()
Gets unmodified offset, NOT modified in case of daylight savings. |
static
String
|
getRegion(String id)
[icu] Returns the region code associated with the given system time zone ID. |
static
String
|
getTZDataVersion()
[icu] Returns the time zone data version currently used by ICU. |
static
TimeZone
|
getTimeZone(String ID, int type)
Gets the |
static
TimeZone
|
getTimeZone(String ID)
Gets the |
static
String
|
getWindowsID(String id)
[icu] Converts a system time zone ID to an equivalent Windows time zone ID. |
boolean
|
hasSameRules(TimeZone other)
Returns true if this zone has the same rule and offset as another zone. |
int
|
hashCode()
Overrides hashCode. |
abstract
boolean
|
inDaylightTime(Date date)
Queries if the given date is in daylight savings time in this time zone. |
boolean
|
isFrozen()
Determines whether the object has been frozen or not. |
boolean
|
observesDaylightTime()
Queries if this time zone is in daylight saving time or will observe daylight saving time at any future time. |
void
|
setID(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. |
Inherited methods | |
---|---|
From
class
java.lang.Object
| |
From
interface
android.icu.util.Freezable
|
int GENERIC_LOCATION
[icu] A style specifier for getDisplayName()
indicating
a long name derived from the timezone's fallback name, such as
"United States (Los Angeles)."
Constant Value: 7 (0x00000007)
int LONG
A style specifier for getDisplayName()
indicating
a long name, such as "Pacific Standard Time."
See also:
Constant Value: 1 (0x00000001)
int LONG_GENERIC
[icu] A style specifier for getDisplayName()
indicating
a long generic name, such as "Pacific Time."
See also:
Constant Value: 3 (0x00000003)
int LONG_GMT
[icu] A style specifier for getDisplayName()
indicating
a long name derived from the timezone's offset, such as "GMT-08:00."
See also:
Constant Value: 5 (0x00000005)
int SHORT
A style specifier for getDisplayName()
indicating
a short name, such as "PST."
See also:
Constant Value: 0 (0x00000000)
int SHORT_COMMONLY_USED
[icu] A style specifier for getDisplayName()
indicating
a short name derived from the timezone's short standard or daylight
timezone name ignoring commonlyUsed, such as "PDT."
Constant Value: 6 (0x00000006)
int SHORT_GENERIC
[icu] A style specifier for getDisplayName()
indicating
a short generic name, such as "PT."
See also:
Constant Value: 2 (0x00000002)
int SHORT_GMT
[icu] A style specifier for getDisplayName()
indicating
a short name derived from the timezone's offset, such as "-0800."
See also:
Constant Value: 4 (0x00000004)
String UNKNOWN_ZONE_ID
[icu] The time zone ID reserved for unknown time zone.
See also:
Constant Value: "Etc/Unknown"
TimeZone GMT_ZONE
[icu] The immutable GMT (=UTC) time zone. Its ID is "Etc/GMT".
TimeZone UNKNOWN_ZONE
[icu] The immutable (frozen) "unknown" time zone.
It behaves like the GMT/UTC time zone but has the UNKNOWN_ZONE_ID = "Etc/Unknown".
getTimeZone(String)
returns a mutable clone of this
time zone if the input ID is not recognized.
See also:
TimeZone ()
Default constructor. (For invocation by subclass constructors, typically implicit.)
Object clone ()
Overrides clone.
Returns | |
---|---|
Object |
a clone of this instance. |
TimeZone cloneAsThawed ()
Provides for the clone operation. Any clone is initially unfrozen.
Returns | |
---|---|
TimeZone |
int countEquivalentIDs (String id)
[icu] Returns the number of IDs in the equivalency group that includes the given ID. An equivalency group contains zones that have the same GMT offset and rules.
The returned count includes the given ID; it is always >= 1 for valid IDs. The given ID must be a system time zone. If it is not, returns zero.
Parameters | |
---|---|
id |
String :
a system time zone ID |
Returns | |
---|---|
int |
the number of zones in the equivalency group containing 'id', or zero if 'id' is not a valid system ID |
See also:
boolean equals (Object obj)
Overrides equals.
Parameters | |
---|---|
obj |
Object :
the reference object with which to compare. |
Returns | |
---|---|
boolean |
true if this object is the same as the obj
argument; false otherwise. |
TimeZone freeze ()
Freezes the object.
Returns | |
---|---|
TimeZone |
the object itself. |
String[] getAvailableIDs ()
Return a new String array containing all system TimeZone IDs.
These IDs (and only these IDs) may be passed to
get()
to construct the corresponding TimeZone
object.
Returns | |
---|---|
String[] |
an array of all system TimeZone IDs |
String[] getAvailableIDs (int rawOffset)
Return a new String array containing all system TimeZone IDs
with the given raw offset from GMT. These IDs may be passed to
get()
to construct the corresponding TimeZone
object.
Parameters | |
---|---|
rawOffset |
int :
the offset in milliseconds from GMT |
Returns | |
---|---|
String[] |
an array of IDs for system TimeZones with the given raw offset. If there are none, return a zero-length array. |
Set<String> getAvailableIDs (TimeZone.SystemTimeZoneType zoneType, String region, Integer rawOffset)
[icu] Returns a set of time zone ID strings with the given filter conditions.
Note:A Set
returned by this method is
immutable.
Parameters | |
---|---|
zoneType |
TimeZone.SystemTimeZoneType :
The system time zone type. |
region |
String :
The ISO 3166 two-letter country code or UN M.49 three-digit area code.
When null, no filtering done by region. |
rawOffset |
Integer :
An offset from GMT in milliseconds, ignoring the effect of daylight savings
time, if any. When null, no filtering done by zone offset. |
Returns | |
---|---|
Set<String> |
an immutable set of system time zone IDs. |
See also:
String[] getAvailableIDs (String country)
Return a new String array containing all system TimeZone IDs
associated with the given country. These IDs may be passed to
get()
to construct the corresponding TimeZone
object.
Parameters | |
---|---|
country |
String :
a two-letter ISO 3166 country code, or null
to return zones not associated with any country |
Returns | |
---|---|
String[] |
an array of IDs for system TimeZones in the given country. If there are none, return a zero-length array. |
String getCanonicalID (String id)
[icu] Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
Parameters | |
---|---|
id |
String :
The input time zone ID to be canonicalized. |
Returns | |
---|---|
String |
The canonical system time zone ID or the custom time zone ID in normalized format for the given time zone ID. When the given time zone ID is neither a known system time zone ID nor a valid custom time zone ID, null is returned. |
String getCanonicalID (String id, boolean[] isSystemID)
[icu] Returns the canonical system time zone ID or the normalized custom time zone ID for the given time zone ID.
Parameters | |
---|---|
id |
String :
The input time zone ID to be canonicalized. |
isSystemID |
boolean :
When non-null boolean array is specified and
the given ID is a known system time zone ID, true is set to isSystemID[0] |
Returns | |
---|---|
String |
The canonical system time zone ID or the custom time zone ID in normalized format for the given time zone ID. When the given time zone ID is neither a known system time zone ID nor a valid custom time zone ID, null is returned. |
int getDSTSavings ()
Returns the amount of time to be added to local standard time to get local wall clock time.
The default implementation always returns 3600000 milliseconds (i.e., one hour) if this time zone observes Daylight Saving Time. Otherwise, 0 (zero) is returned.
If an underlying TimeZone implementation subclass supports historical Daylight Saving Time changes, this method returns the known latest daylight saving value.
Returns | |
---|---|
int |
the amount of saving time in milliseconds |
TimeZone getDefault ()
Gets the default TimeZone
for this host.
The source of the default TimeZone
may vary with implementation.
Returns | |
---|---|
TimeZone |
a default TimeZone .
|
String getDisplayName (boolean daylight, int style, Locale locale)
Returns a name of this time zone suitable for presentation to the user
in the specified locale.
If the display name is not available for the locale,
then this method returns a string in the localized GMT offset format
such as GMT[+-]HH:mm
.
Parameters | |
---|---|
daylight |
boolean :
if true, return the daylight savings name. |
style |
int :
the output style of the display name. Valid styles are
SHORT , LONG , SHORT_GENERIC ,
LONG_GENERIC , SHORT_GMT , LONG_GMT ,
SHORT_COMMONLY_USED or GENERIC_LOCATION . |
locale |
Locale :
the locale in which to supply the display name. |
Returns | |
---|---|
String |
the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized. |
Throws | |
---|---|
IllegalArgumentException |
style is invalid. |
String getDisplayName ()
Returns a name of this time zone suitable for presentation to the user
in the default DISPLAY
locale.
This method returns the long generic name.
If the display name is not available for the locale,
a fallback based on the country, city, or time zone id will be used.
Returns | |
---|---|
String |
the human-readable name of this time zone in the default locale. |
See also:
String getDisplayName (ULocale locale)
Returns a name of this time zone suitable for presentation to the user in the specified locale. This method returns the long name, not including daylight savings. If the display name is not available for the locale, a fallback based on the country, city, or time zone id will be used.
Parameters | |
---|---|
locale |
ULocale :
the ulocale in which to supply the display name. |
Returns | |
---|---|
String |
the human-readable name of this time zone in the given locale or in the default ulocale if the given ulocale is not recognized. |
String getDisplayName (boolean daylight, int style, ULocale locale)
Returns a name of this time zone suitable for presentation to the user
in the specified locale.
If the display name is not available for the locale,
then this method returns a string in the localized GMT offset format
such as GMT[+-]HH:mm
.
Parameters | |
---|---|
daylight |
boolean :
if true, return the daylight savings name. |
style |
int :
the output style of the display name. Valid styles are
SHORT , LONG , SHORT_GENERIC ,
LONG_GENERIC , SHORT_GMT , LONG_GMT ,
SHORT_COMMONLY_USED or GENERIC_LOCATION . |
locale |
ULocale :
the locale in which to supply the display name. |
Returns | |
---|---|
String |
the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized. |
Throws | |
---|---|
IllegalArgumentException |
style is invalid. |
String getDisplayName (Locale locale)
Returns a name of this time zone suitable for presentation to the user in the specified locale. This method returns the long generic name. If the display name is not available for the locale, a fallback based on the country, city, or time zone id will be used.
Parameters | |
---|---|
locale |
Locale :
the locale in which to supply the display name. |
Returns | |
---|---|
String |
the human-readable name of this time zone in the given locale or in the default locale if the given locale is not recognized. |
String getDisplayName (boolean daylight, int style)
Returns a name of this time zone suitable for presentation to the user
in the default DISPLAY
locale.
If the display name is not available for the locale,
then this method returns a string in the localized GMT offset format
such as GMT[+-]HH:mm
.
Parameters | |
---|---|
daylight |
boolean :
if true, return the daylight savings name. |
style |
int :
the output style of the display name. Valid styles are
SHORT , LONG , SHORT_GENERIC ,
LONG_GENERIC , SHORT_GMT , LONG_GMT ,
SHORT_COMMONLY_USED or GENERIC_LOCATION . |
Returns | |
---|---|
String |
the human-readable name of this time zone in the default locale. |
See also:
String getEquivalentID (String id, int index)
Returns an ID in the equivalency group that includes the given ID. An equivalency group contains zones that have the same GMT offset and rules.
The given index must be in the range 0..n-1, where n is the
value returned by countEquivalentIDs(id)
. For
some value of 'index', the returned value will be equal to the
given id. If the given id is not a valid system time zone, or
if 'index' is out of range, then returns an empty string.
Parameters | |
---|---|
id |
String :
a system time zone ID |
index |
int :
a value from 0 to n-1, where n is the value
returned by countEquivalentIDs(id) |
Returns | |
---|---|
String |
the ID of the index-th zone in the equivalency group containing 'id', or an empty string if 'id' is not a valid system ID or 'index' is out of range |
See also:
TimeZone getFrozenTimeZone (String ID)
Gets the TimeZone
for the given ID. The instance of TimeZone
returned by this method is immutable. Any methods mutate the instance(setID(String)
,
setRawOffset(int)
) will throw UnsupportedOperationException
upon its
invocation.
Parameters | |
---|---|
ID |
String :
the ID for a TimeZone , such as "America/Los_Angeles",
or a custom ID such as "GMT-8:00". Note that the support of abbreviations,
such as "PST", is for JDK 1.1.x compatibility only and full names should be used. |
Returns | |
---|---|
TimeZone |
the specified TimeZone , or the UNKNOWN_ZONE
if the given ID cannot be understood. |
See also:
String getID ()
Gets the ID of this time zone.
Returns | |
---|---|
String |
the ID of this time zone. |
String getIDForWindowsID (String winid, String region)
[icu] Converts a Windows time zone ID to an equivalent system time zone ID
for a region. For example, system time zone ID "America/Los_Angeles" is returned
for input Windows ID "Pacific Standard Time" and region "US" (or null
),
"America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and
region "CA".
Not all Windows time zones can be mapped to system time zones. When the input
Windows time zone ID is unknown or unmappable to a system time zone, then this
method returns null
.
This implementation utilizes Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes, please read the ICU user guide section Updating the Time Zone Data.
Parameters | |
---|---|
winid |
String :
A Windows time zone ID |
region |
String :
A region code, or null if no regional preference. |
Returns | |
---|---|
String |
A system time zone ID mapped from the input Windows time zone ID,
or null when the input ID is unknown or unmappable. |
See also:
void getOffset (long date, boolean local, int[] offsets)
Returns the time zone raw and GMT offset for the given moment in time. Upon return, local-millis = GMT-millis + rawOffset + dstOffset. All computations are performed in the proleptic Gregorian calendar. The default implementation in the TimeZone class delegates to the 8-argument getOffset().
Parameters | |
---|---|
date |
long :
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 |
boolean :
if true, `date' is local wall time; otherwise it
is in GMT time. |
offsets |
int :
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.
|
int getOffset (long date)
Returns the offset of this time zone from UTC at the specified date. If Daylight Saving Time is in effect at the specified date, the offset value is adjusted with the amount of daylight saving.
Parameters | |
---|---|
date |
long :
the date represented in milliseconds since January 1, 1970 00:00:00 GMT |
Returns | |
---|---|
int |
the amount of time in milliseconds to add to UTC to get local time. |
int getOffset (int era, int year, int month, int day, int dayOfWeek, int milliseconds)
Gets the time zone offset, for current date, modified in case of daylight savings. This is the offset to add *to* UTC to get local time.
Parameters | |
---|---|
era |
int :
the era of the given date. |
year |
int :
the year in the given date. |
month |
int :
the month in the given date.
Month is 0-based. e.g., 0 for January. |
day |
int :
the day-in-month of the given date. |
dayOfWeek |
int :
the day-of-week of the given date. |
milliseconds |
int :
the millis in day in standard local time. |
Returns | |
---|---|
int |
the offset to add *to* GMT to get local time. |
int getRawOffset ()
Gets unmodified offset, NOT modified in case of daylight savings. This is the offset to add *to* UTC to get local time.
Returns | |
---|---|
int |
the unmodified offset to add *to* UTC to get local time. |
String getRegion (String id)
[icu] Returns the region code associated with the given system time zone ID. The region code is either ISO 3166 2-letter country code or UN M.49 3-digit area code. When the time zone is not associated with a specific location, for example - "Etc/UTC", "EST5EDT", then this method returns "001" (UN M.49 area code for World).
Parameters | |
---|---|
id |
String :
the system time zone ID. |
Returns | |
---|---|
String |
the region code associated with the given system time zone ID. |
Throws | |
---|---|
IllegalArgumentException |
if id is not a known system ID. |
See also:
String getTZDataVersion ()
[icu] Returns the time zone data version currently used by ICU.
Returns | |
---|---|
String |
the version string, such as "2007f" |
Throws | |
---|---|
MissingResourceException |
if ICU time zone resource bundle is missing or the version information is not available. |
TimeZone getTimeZone (String ID, int type)
Gets the TimeZone
for the given ID and the timezone type.
Parameters | |
---|---|
ID |
String :
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 |
int :
Time zone type, either TIMEZONE_ICU or
TIMEZONE_JDK . |
Returns | |
---|---|
TimeZone |
the specified TimeZone , or a mutable clone of the UNKNOWN_ZONE if the given ID
cannot be understood or if the given ID is "Etc/Unknown". |
See also:
TimeZone getTimeZone (String ID)
Gets the TimeZone
for the given ID.
Parameters | |
---|---|
ID |
String :
the ID for a TimeZone , such as "America/Los_Angeles",
or a custom ID such as "GMT-8:00". Note that the support of abbreviations,
such as "PST", is for JDK 1.1.x compatibility only and full names should be used. |
Returns | |
---|---|
TimeZone |
the specified TimeZone , or a mutable clone of the UNKNOWN_ZONE
if the given ID cannot be understood or if the given ID is "Etc/Unknown". |
See also:
String getWindowsID (String id)
[icu] Converts a system time zone ID to an equivalent Windows time zone ID. For example, Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles".
There are system time zones that cannot be mapped to Windows zones. When the input
system time zone ID is unknown or unmappable to a Windows time zone, then this
method returns null
.
This implementation utilizes Zone-Tzid mapping data. The mapping data is updated time to time. To get the latest changes, please read the ICU user guide section Updating the Time Zone Data.
Parameters | |
---|---|
id |
String :
A system time zone ID |
Returns | |
---|---|
String |
A Windows time zone ID mapped from the input system time zone ID,
or null when the input ID is unknown or unmappable. |
See also:
boolean hasSameRules (TimeZone other)
Returns true if this zone has the same rule and offset as another zone. That is, if this zone differs only in ID, if at all. Returns false if the other zone is null.
Parameters | |
---|---|
other |
TimeZone :
the TimeZone object to be compared with |
Returns | |
---|---|
boolean |
true if the other zone is not null and is the same as this one, with the possible exception of the ID |
int hashCode ()
Overrides hashCode.
Returns | |
---|---|
int |
a hash code value for this object. |
boolean inDaylightTime (Date date)
Queries if the given date is in daylight savings time in this time zone.
Parameters | |
---|---|
date |
Date :
the given Date. |
Returns | |
---|---|
boolean |
true if the given date is in daylight savings time, false, otherwise. |
boolean isFrozen ()
Determines whether the object has been frozen or not.
Returns | |
---|---|
boolean |
boolean observesDaylightTime ()
Queries if this time zone is in daylight saving time or will observe daylight saving time at any future time.
The default implementation in this class returns true
if useDaylightTime()
or inDaylightTime(new Date())
returns true
.
Note: This method was added for TimeZone
compatibility
support. The useDaylightTime()
method only checks the last known
rule(s), therefore it may return false even the zone observes daylight saving time currently.
TimeZone
added observesDaylightTime()
to resolve the issue.
In ICU, useDaylightTime()
works differently. The ICU implementation checks if the
zone uses daylight saving time in the current calendar year. Therefore, it will never return
false
if daylight saving time is currently used.
ICU's TimeZone subclass implementations override this method to support the same behavior
with observesDaylightTime()
. Unlike useDaylightTime()
,
the implementation does not take past daylight saving time into account, so
that this method may return false
even when useDaylightTime()
returns
true
.
Returns | |
---|---|
boolean |
true if this time zone is in daylight saving time or will observe
daylight saving time at any future time. |
See also:
void setID (String ID)
Sets the time zone ID. This does not change any other data in the time zone object.
Parameters | |
---|---|
ID |
String :
the new time zone ID.
|
void setRawOffset (int offsetMillis)
Sets the base time zone offset to GMT. This is the offset to add *to* UTC to get local time.
Parameters | |
---|---|
offsetMillis |
int :
the given base time zone offset to GMT.
|
boolean useDaylightTime ()
Queries if this time zone uses daylight savings time.
Returns | |
---|---|
boolean |
true if this time zone uses daylight savings time,
false, otherwise.
Note:The default implementation of
ICU TimeZone uses the tz database, which supports historic
rule changes, for system time zones. With the implementation,
there are time zones that used daylight savings time in the
past, but no longer used currently. For example, Asia/Tokyo has
never used daylight savings time since 1951. Most clients would
expect that this method to return |