com.ibm.icu.util

Class BasicTimeZone

java.lang.Object

com.ibm.icu.util.TimeZone

com.ibm.icu.util.BasicTimeZone

All Implemented Interfaces:

Freezable<TimeZone>, Serializable, Cloneable

Direct Known Subclasses:

RuleBasedTimeZone, SimpleTimeZone, VTimeZone

public abstract class BasicTimeZone
extends TimeZone

[icu] BasicTimeZone extends TimeZone with additional methods to access time zone transitions and rules. All ICU TimeZone concrete subclasses extend this class. APIs added to java.util.TimeZone by BasicTimeZone are annotated with '[icu]'.

See Also:

TimeZoneRule, TimeZoneTransition, Serialized Form

Status:

Stable ICU 3.8.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BasicTimeZone.LocalOption [icu] Options used by getOffsetFromLocal(long, LocalOption, LocalOption, int[]) to specify how to interpret an input time when it does not exist, or when it is ambiguous, around a time zone transition.

Nested classes/interfaces inherited from class com.ibm.icu.util.TimeZone

TimeZone.SystemTimeZoneType

Field Summary

Fields

Modifier and Type	Field and Description
protected static int	FORMER_LATTER_MASK Deprecated. This API is ICU internal only.
protected static int	LOCAL_DST Deprecated. This API is ICU internal only.
protected static int	LOCAL_FORMER Deprecated. This API is ICU internal only.
protected static int	LOCAL_LATTER Deprecated. This API is ICU internal only.
protected static int	LOCAL_STD Deprecated. This API is ICU internal only.
protected static int	STD_DST_MASK Deprecated. This API is ICU internal only.

Fields inherited from class com.ibm.icu.util.TimeZone

GENERIC_LOCATION, GMT_ZONE, LONG, LONG_GENERIC, LONG_GMT, SHORT, SHORT_COMMONLY_USED, SHORT_GENERIC, SHORT_GMT, TIMEZONE_ICU, TIMEZONE_JDK, UNKNOWN_ZONE, UNKNOWN_ZONE_ID

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicTimeZone() Protected no arg constructor.
protected	BasicTimeZone(String ID) Deprecated. This API is ICU internal only.

Method Summary

Modifier and Type	Method and Description
protected static int	getLocalOptionValue(BasicTimeZone.LocalOption locOpt) Deprecated. This API is ICU internal only.
abstract TimeZoneTransition	getNextTransition(long base, boolean inclusive) [icu] Returns the first time zone transition after the base time.
void	getOffsetFromLocal(long date, BasicTimeZone.LocalOption nonExistingTimeOpt, BasicTimeZone.LocalOption duplicatedTimeOpt, int[] offsets) [icu] Returns time zone offsets from local wall time.
abstract TimeZoneTransition	getPreviousTransition(long base, boolean inclusive) [icu] Returns the last time zone transition before the base time.
TimeZoneRule[]	getSimpleTimeZoneRulesNear(long date) [icu] Returns the array of TimeZoneRule which represents the rule of this time zone object near the specified date.
abstract TimeZoneRule[]	getTimeZoneRules() [icu] Returns the array of TimeZoneRule which represents the rule of this time zone object.
TimeZoneRule[]	getTimeZoneRules(long start) [icu] Returns the array of TimeZoneRule which represents the rule of this time zone object since the specified start time.
boolean	hasEquivalentTransitions(TimeZone tz, long start, long end) [icu] Checks if the time zone has equivalent transitions in the time range.
boolean	hasEquivalentTransitions(TimeZone tz, long start, long end, boolean ignoreDstAmount) [icu] Checks if the time zone has equivalent transitions in the time range.

Methods inherited from class com.ibm.icu.util.TimeZone

clone, cloneAsThawed, countEquivalentIDs, equals, forLocaleOrDefault, forULocaleOrDefault, freeze, getAvailableIDs, getAvailableIDs, getAvailableIDs, getAvailableIDs, getCanonicalID, getCanonicalID, getDefault, getDefaultTimeZoneType, getDisplayName, getDisplayName, getDisplayName, getDisplayName, getDisplayName, getDisplayName, getDSTSavings, getEquivalentID, getFrozenTimeZone, getIanaID, getID, getIDForWindowsID, getOffset, getOffset, getOffset, getRawOffset, getRegion, getTimeZone, getTimeZone, getTZDataVersion, getWindowsID, hashCode, hasSameRules, inDaylightTime, isFrozen, observesDaylightTime, setDefault, setDefaultTimeZoneType, setICUDefault, setID, setRawOffset, useDaylightTime

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOCAL_STD

@Deprecated
protected static final int LOCAL_STD

Deprecated. This API is ICU internal only.

The time type option for standard time used by internal implementation.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

LOCAL_DST

@Deprecated
protected static final int LOCAL_DST

Deprecated. This API is ICU internal only.

The time type option for daylight saving time used internally.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

LOCAL_FORMER

@Deprecated
protected static final int LOCAL_FORMER

Deprecated. This API is ICU internal only.

The option designate former time used by internal implementation.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

LOCAL_LATTER

@Deprecated
protected static final int LOCAL_LATTER

Deprecated. This API is ICU internal only.

The option designate latter time used by internal implementation.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

STD_DST_MASK

@Deprecated
protected static final int STD_DST_MASK

Deprecated. This API is ICU internal only.

The bit mask for the time type option used by internal implementation.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

FORMER_LATTER_MASK

@Deprecated
protected static final int FORMER_LATTER_MASK

Deprecated. This API is ICU internal only.

The bit mask for the former/latter option used by internal implementation.

See Also:

Constant Field Values

Status:

Internal. This API is ICU internal only.

Constructor Detail

BasicTimeZone

protected BasicTimeZone()

Protected no arg constructor.

Status:

Stable ICU 3.8.

BasicTimeZone

@Deprecated
protected BasicTimeZone(String ID)

Deprecated. This API is ICU internal only.

Constructing a BasicTimeZone with the given time zone ID.

Parameters:

ID - the time zone ID.

Status:

Internal. This API is ICU internal only.

Method Detail

getNextTransition

public abstract TimeZoneTransition getNextTransition(long base,
                                                     boolean inclusive)

[icu] Returns the first time zone transition after the base time.

Example code:

System.out.println("### Iterates time zone transitions in America/Los_Angeles starting 2005-01-01 and forward");

// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);

// Date format for the wall time
SimpleDateFormat wallTimeFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", ULocale.US);
wallTimeFmt.setTimeZone(btz);

long start = 1104537600000L;    // 2005-01-01 0:00 UTC
for (int i = 0; i < 5; i++) {   // Up to 5 transitions
    TimeZoneTransition trans = btz.getNextTransition(start, false /* not including start time */);

    // Display the transition time and offset information
    long transTime = trans.getTime();
    System.out.println(wallTimeFmt.format(new Date(transTime - 1)) + " -> " + wallTimeFmt.format(new Date(transTime)));
    System.out.println(" - Before (Offset/Save): " + trans.getFrom().getRawOffset() + "/" + trans.getFrom().getDSTSavings());
    System.out.println(" - After  (Offset/Save): " + trans.getTo().getRawOffset() + "/" + trans.getTo().getDSTSavings());

    // Update start time for next transition
    start = transTime;
}

Parameters:

base - The base time.

inclusive - Whether the base time is inclusive or not.

Returns:

A Date holding the first time zone transition time after the given base time, or null if no time zone transitions are available after the base time.

Status:

Stable ICU 3.8.

getPreviousTransition

public abstract TimeZoneTransition getPreviousTransition(long base,
                                                         boolean inclusive)

[icu] Returns the last time zone transition before the base time.

Example code:

System.out.println("### Iterates time zone transitions in America/Los_Angeles starting 2010-01-01 and backward");

// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);

// Date format for the wall time
SimpleDateFormat wallTimeFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", ULocale.US);
wallTimeFmt.setTimeZone(btz);

long start = 1262304000000L;    // 2010-01-01 0:00 UTC
for (int i = 0; i < 5; i++) {   // Up to 5 transitions
    TimeZoneTransition trans = btz.getPreviousTransition(start, false /* not including start time */);

    // Display the transition time and offset information
    long transTime = trans.getTime();
    System.out.println(wallTimeFmt.format(new Date(transTime - 1)) + " -> " + wallTimeFmt.format(new Date(transTime)));
    System.out.println(" - Before (Offset/Save): " + trans.getFrom().getRawOffset() + "/" + trans.getFrom().getDSTSavings());
    System.out.println(" - After  (Offset/Save): " + trans.getTo().getRawOffset() + "/" + trans.getTo().getDSTSavings());

    // Update start time for next transition
    start = transTime;
}

Parameters:

base - The base time.

inclusive - Whether the base time is inclusive or not.

Returns:

A Date holding the last time zone transition time before the given base time, or null if no time zone transitions are available before the base time.

Status:

Stable ICU 3.8.

hasEquivalentTransitions

public boolean hasEquivalentTransitions(TimeZone tz,
                                        long start,
                                        long end)

[icu] Checks if the time zone has equivalent transitions in the time range. This method returns true when all of transition times, from/to standard offsets and DST savings used by this time zone match the other in the time range.

Example code:

System.out.println("### Compare America/New_York and America/Detroit since year 1970");

// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone tzNewYork = (BasicTimeZone)TimeZone.getTimeZone("America/New_York", TimeZone.TIMEZONE_ICU);
BasicTimeZone tzDetroit = (BasicTimeZone)TimeZone.getTimeZone("America/Detroit", TimeZone.TIMEZONE_ICU);

GregorianCalendar cal = new GregorianCalendar(TimeZone.getTimeZone("Etc/GMT"));

// Compare these time zones every 10 years since year 1970 up to year 2009
for (int startYear = 1970; startYear <= 2000; startYear += 10) {
    long start, end;

    cal.set(startYear, Calendar.JANUARY, 1, 0, 0, 0);
    cal.set(Calendar.MILLISECOND, 0);
    start = cal.getTimeInMillis();

    // Set the end time to the end of startYear + 9
    int endYear = startYear + 9;
    cal.set(endYear + 1, Calendar.JANUARY, 1, 0, 0, 0);
    end = cal.getTimeInMillis() - 1;

    // Check if these two zones have equivalent time zone transitions for the given time range
    boolean isEquivalent = tzNewYork.hasEquivalentTransitions(tzDetroit, start, end);
    System.out.println(startYear + "-" + endYear + ": " + isEquivalent);
}

Parameters:

tz - The instance of TimeZone

start - The start time of the evaluated time range (inclusive)

end - The end time of the evaluated time range (inclusive)

Returns:

true if the other time zone has the equivalent transitions in the time range. When tz is not a BasicTimeZone, this method returns false.

Status:

Stable ICU 3.8.

hasEquivalentTransitions

public boolean hasEquivalentTransitions(TimeZone tz,
                                        long start,
                                        long end,
                                        boolean ignoreDstAmount)

[icu] Checks if the time zone has equivalent transitions in the time range. This method returns true when all of transition times, from/to standard offsets and DST savings used by this time zone match the other in the time range.

Parameters:

tz - The instance of TimeZone

start - The start time of the evaluated time range (inclusive)

end - The end time of the evaluated time range (inclusive)

ignoreDstAmount - When true, any transitions with only daylight saving amount changes will be ignored, except either of them is zero. For example, a transition from rawoffset 3:00/dstsavings 1:00 to rawoffset 2:00/dstsavings 2:00 is excluded from the comparison, but a transition from rawoffset 2:00/dstsavings 1:00 to rawoffset 3:00/dstsavings 0:00 is included.

Returns:

true if the other time zone has the equivalent transitions in the time range. When tz is not a BasicTimeZone, this method returns false.

Status:

Stable ICU 3.8.

getTimeZoneRules

public abstract TimeZoneRule[] getTimeZoneRules()

[icu] Returns the array of TimeZoneRule which represents the rule of this time zone object. The first element in the result array will be the InitialTimeZoneRule instance for the initial rule. The rest will be either AnnualTimeZoneRule or TimeArrayTimeZoneRule instances representing transitions.

Returns:

The array of TimeZoneRule which represents this time zone.

Status:

Stable ICU 3.8.

getTimeZoneRules

public TimeZoneRule[] getTimeZoneRules(long start)

[icu] Returns the array of TimeZoneRule which represents the rule of this time zone object since the specified start time. The first element in the result array will be the InitialTimeZoneRule instance for the initial rule. The rest will be either AnnualTimeZoneRule or TimeArrayTimeZoneRule instances representing transitions.

Example code:

System.out.println("### Extracts time zone rules used by America/Los_Angeles since year 2005");

// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);
long since = 1104537600000L;    // 2005-01-01 0:00 UTC
TimeZoneRule[] rules = btz.getTimeZoneRules(since);
System.out.println("Rule(initial): " + rules[0]);
for (int i = 1; i < rules.length; i++) {
    System.out.println("Rule: " + rules[i]);
}

Parameters:

start - The start time (inclusive).

Returns:

The array of TimeZoneRule which represents this time zone since the start time.

Status:

Stable ICU 3.8.

getSimpleTimeZoneRulesNear

public TimeZoneRule[] getSimpleTimeZoneRulesNear(long date)

[icu] Returns the array of TimeZoneRule which represents the rule of this time zone object near the specified date. Some applications are not capable to handle historic time zone rule changes. Also some applications can only handle certain type of rule definitions. This method returns either a single InitialTimeZoneRule if this time zone does not have any daylight saving time within 1 year from the specified time, or a pair of AnnualTimeZoneRule whose rule type is DateTimeRule.DOW for date and DateTimeRule.WALL_TIME for time with a single InitialTimeZoneRule representing the initial time, when this time zone observes daylight saving time near the specified date. Thus, the result may be only valid for dates around the specified date.

Parameters:

date - The date to be used for TimeZoneRule extraction.

Returns:

The array of TimeZoneRule, either a single InitialTimeZoneRule object, or a pair of AnnualTimeZoneRule with a single InitialTimeZoneRule. The first element in the array is always a InitialTimeZoneRule.

Status:

Stable ICU 3.8.

getLocalOptionValue

@Deprecated
protected static int getLocalOptionValue(BasicTimeZone.LocalOption locOpt)

Deprecated. This API is ICU internal only.

Get BasicTimeZone.LocalOption's internal flag value. This is used by ICU internal implementation only.

Parameters:

locOpt - A LocalOption

Returns:

LocalOption's internal flag value.

Status:

Internal. This API is ICU internal only.

getOffsetFromLocal

public void getOffsetFromLocal(long date,
                               BasicTimeZone.LocalOption nonExistingTimeOpt,
                               BasicTimeZone.LocalOption duplicatedTimeOpt,
                               int[] offsets)

[icu] Returns time zone offsets from local wall time.

Status:

Stable ICU 69.