Class SimpleTimeZone
java.lang.Object
java.util.TimeZone
java.util.SimpleTimeZone
- All Implemented Interfaces:
Serializable,Cloneable
SimpleTimeZone is a concrete subclass of TimeZone
that represents a time zone for use with a Gregorian calendar.
The class holds an offset from GMT, called raw offset, and start
and end rules for a daylight saving time schedule. Since it only holds
single values for each, it cannot handle historical changes in the offset
from GMT and the daylight saving schedule, except that the setStartYear method can specify the year when the daylight
saving time schedule starts in effect.
To construct a SimpleTimeZone with a daylight saving time
schedule, the schedule can be described with a set of rules,
start-rule and end-rule. A day when daylight saving time
starts or ends is specified by a combination of month,
day-of-month, and day-of-week values. The month
value is represented by a Calendar MONTH field
value, such as Calendar.MARCH. The day-of-week value is
represented by a Calendar DAY_OF_WEEK value,
such as SUNDAY. The meanings of value combinations
are as follows.
- Exact day of month
To specify an exact day of month, set the month and day-of-month to an exact value, and day-of-week to zero. For example, to specify March 1, set the month toMARCH, day-of-month to 1, and day-of-week to 0. - Day of week on or after day of month
To specify a day of week on or after an exact day of month, set the month to an exact month value, day-of-month to the day on or after which the rule is applied, and day-of-week to a negativeDAY_OF_WEEKfield value. For example, to specify the second Sunday of April, set month toAPRIL, day-of-month to 8, and day-of-week to-SUNDAY. - Day of week on or before day of month
To specify a day of the week on or before an exact day of the month, set day-of-month and day-of-week to a negative value. For example, to specify the last Wednesday on or before the 21st of March, set month toMARCH, day-of-month is -21 and day-of-week is-WEDNESDAY. - Last day-of-week of month
To specify, the last day-of-week of the month, set day-of-week to aDAY_OF_WEEKvalue and day-of-month to -1. For example, to specify the last Sunday of October, set month toOCTOBER, day-of-week toSUNDAYand day-of-month to -1.
WALL_TIME, STANDARD_TIME and UTC_TIME. For example, if daylight
saving time ends
at 2:00 am in the wall clock time, it can be specified by 7200000
milliseconds in the WALL_TIME mode. In this case, the wall clock time
for an end-rule means the same thing as the daylight time.
The following are examples of parameters for constructing time zone objects.
// Base GMT offset: -8:00
// DST starts: at 2:00am in standard time
// on the first Sunday in April
// DST ends: at 2:00am in daylight time
// on the last Sunday in October
// Save: 1 hour
SimpleTimeZone(-28800000,
"America/Los_Angeles",
Calendar.APRIL, 1, -Calendar.SUNDAY,
7200000,
Calendar.OCTOBER, -1, Calendar.SUNDAY,
7200000,
3600000)
// Base GMT offset: +1:00
// DST starts: at 1:00am in UTC time
// on the last Sunday in March
// DST ends: at 1:00am in UTC time
// on the last Sunday in October
// Save: 1 hour
SimpleTimeZone(3600000,
"Europe/Paris",
Calendar.MARCH, -1, Calendar.SUNDAY,
3600000, SimpleTimeZone.UTC_TIME,
Calendar.OCTOBER, -1, Calendar.SUNDAY,
3600000, SimpleTimeZone.UTC_TIME,
3600000)
These parameter rules are also applicable to the set rule methods, such as
setStartRule.- Since:
- 1.1
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final intConstant for a mode of start or end time specified as standard time.static final intConstant for a mode of start or end time specified as UTC.static final intConstant for a mode of start or end time specified as wall clock time. -
Constructor Summary
ConstructorsConstructorDescriptionSimpleTimeZone(int rawOffset, String ID) Constructs a SimpleTimeZone with the given base time zone offset from GMT and time zone ID with no daylight saving time schedule.SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time.SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime, int dstSavings) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time.SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int startTimeMode, int endMonth, int endDay, int endDayOfWeek, int endTime, int endTimeMode, int dstSavings) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time. -
Method Summary
Modifier and TypeMethodDescriptionclone()Returns a clone of thisSimpleTimeZoneinstance.booleanCompares the equality of twoSimpleTimeZoneobjects.intReturns the amount of time in milliseconds that the clock is advanced during daylight saving time.intgetOffset(int era, int year, int month, int day, int dayOfWeek, int millis) Returns the difference in milliseconds between local time and UTC, taking into account both the raw offset and the effect of daylight saving, for the specified date and time.intgetOffset(long date) Returns the offset of this time zone from UTC at the given time.intGets the GMT offset for this time zone.inthashCode()Generates the hash code for the SimpleDateFormat object.booleanhasSameRules(TimeZone other) Returnstrueif this zone has the same rules and offset as another zone.booleaninDaylightTime(Date date) Queries if the given date is in daylight saving time.booleanReturnstrueif thisSimpleTimeZoneobserves Daylight Saving Time.voidsetDSTSavings(int millisSavedDuringDST) Sets the amount of time in milliseconds that the clock is advanced during daylight saving time.voidsetEndRule(int endMonth, int endDay, int endTime) Sets the daylight saving time end rule to a fixed date within a month.voidsetEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime) Sets the daylight saving time end rule.voidsetEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime, boolean after) Sets the daylight saving time end rule to a weekday before or after the given date within a month, e.g., the first Monday on or after the 8th.voidsetRawOffset(int offsetMillis) Sets the base time zone offset to GMT.voidsetStartRule(int startMonth, int startDay, int startTime) Sets the daylight saving time start rule to a fixed date within a month.voidsetStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime) Sets the daylight saving time start rule.voidsetStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime, boolean after) Sets the daylight saving time start rule to a weekday before or after the given date within a month, e.g., the first Monday on or after the 8th.voidsetStartYear(int year) Sets the daylight saving time starting year.toString()Returns a string representation of this time zone.booleanQueries if this time zone uses daylight saving time.Methods declared in class java.util.TimeZone
getAvailableIDs, getAvailableIDs, getDefault, getDisplayName, getDisplayName, getDisplayName, getDisplayName, getID, getTimeZone, getTimeZone, setDefault, setID, toZoneId
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Field Details
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WALL_TIME
public static final int WALL_TIMEConstant for a mode of start or end time specified as wall clock time. Wall clock time is standard time for the onset rule, and daylight time for the end rule.- Since:
- 1.4
- See Also:
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STANDARD_TIME
public static final int STANDARD_TIMEConstant for a mode of start or end time specified as standard time.- Since:
- 1.4
- See Also:
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UTC_TIME
public static final int UTC_TIMEConstant for a mode of start or end time specified as UTC. European Union rules are specified as UTC time, for example.- Since:
- 1.4
- See Also:
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Constructor Details
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SimpleTimeZone
Constructs a SimpleTimeZone with the given base time zone offset from GMT and time zone ID with no daylight saving time schedule.- Parameters:
rawOffset- The base time zone offset in milliseconds to GMT.ID- The time zone name that is given to this instance.
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SimpleTimeZone
public SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time. BothstartTimeandendTimeare specified to be represented in the wall clock time. The amount of daylight saving is assumed to be 3600000 milliseconds (i.e., one hour). This constructor is equivalent to:SimpleTimeZone(rawOffset, ID, startMonth, startDay, startDayOfWeek, startTime, SimpleTimeZone.WALL_TIME, endMonth, endDay, endDayOfWeek, endTime, SimpleTimeZone.WALL_TIME, 3600000)- Parameters:
rawOffset- The given base time zone offset from GMT.ID- The time zone ID which is given to this object.startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts. See the class description for the special cases of this parameter.startDayOfWeek- The daylight saving time starting day-of-week. See the class description for the special cases of this parameter.startTime- The daylight saving time starting time in local wall clock time (in milliseconds within the day), which is local standard time in this case.endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends. See the class description for the special cases of this parameter.endDayOfWeek- The daylight saving time ending day-of-week. See the class description for the special cases of this parameter.endTime- The daylight saving ending time in local wall clock time, (in milliseconds within the day) which is local daylight time in this case.- Throws:
IllegalArgumentException- if the month, day, dayOfWeek, or time parameters are out of range for the start or end rule
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SimpleTimeZone
public SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime, int dstSavings) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time. BothstartTimeandendTimeare assumed to be represented in the wall clock time. This constructor is equivalent to:SimpleTimeZone(rawOffset, ID, startMonth, startDay, startDayOfWeek, startTime, SimpleTimeZone.WALL_TIME, endMonth, endDay, endDayOfWeek, endTime, SimpleTimeZone.WALL_TIME, dstSavings)- Parameters:
rawOffset- The given base time zone offset from GMT.ID- The time zone ID which is given to this object.startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts. See the class description for the special cases of this parameter.startDayOfWeek- The daylight saving time starting day-of-week. See the class description for the special cases of this parameter.startTime- The daylight saving time starting time in local wall clock time, which is local standard time in this case.endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends. See the class description for the special cases of this parameter.endDayOfWeek- The daylight saving time ending day-of-week. See the class description for the special cases of this parameter.endTime- The daylight saving ending time in local wall clock time, which is local daylight time in this case.dstSavings- The amount of time in milliseconds saved during daylight saving time.- Throws:
IllegalArgumentException- if the month, day, dayOfWeek, or time parameters are out of range for the start or end rule- Since:
- 1.2
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SimpleTimeZone
public SimpleTimeZone(int rawOffset, String ID, int startMonth, int startDay, int startDayOfWeek, int startTime, int startTimeMode, int endMonth, int endDay, int endDayOfWeek, int endTime, int endTimeMode, int dstSavings) Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, and rules for starting and ending the daylight time. This constructor takes the full set of the start and end rules parameters, including modes ofstartTimeandendTime. The mode specifies eitherwall timeorstandard timeorUTC time.- Parameters:
rawOffset- The given base time zone offset from GMT.ID- The time zone ID which is given to this object.startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts. See the class description for the special cases of this parameter.startDayOfWeek- The daylight saving time starting day-of-week. See the class description for the special cases of this parameter.startTime- The daylight saving time starting time in the time mode specified bystartTimeMode.startTimeMode- The mode of the start time specified by startTime.endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends. See the class description for the special cases of this parameter.endDayOfWeek- The daylight saving time ending day-of-week. See the class description for the special cases of this parameter.endTime- The daylight saving ending time in time mode specified byendTimeMode.endTimeMode- The mode of the end time specified by endTimedstSavings- The amount of time in milliseconds saved during daylight saving time.- Throws:
IllegalArgumentException- if the month, day, dayOfWeek, time more, or time parameters are out of range for the start or end rule, or if a time mode value is invalid.- Since:
- 1.4
- See Also:
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Method Details
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setStartYear
public void setStartYear(int year) Sets the daylight saving time starting year.- Parameters:
year- The daylight saving starting year.
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setStartRule
public void setStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime) Sets the daylight saving time start rule. For example, if daylight saving time starts on the first Sunday in April at 2 am in local wall clock time, you can set the start rule by calling:setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);- Parameters:
startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts. See the class description for the special cases of this parameter.startDayOfWeek- The daylight saving time starting day-of-week. See the class description for the special cases of this parameter.startTime- The daylight saving time starting time in local wall clock time, which is local standard time in this case.- Throws:
IllegalArgumentException- if thestartMonth,startDay,startDayOfWeek, orstartTimeparameters are out of range
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setStartRule
public void setStartRule(int startMonth, int startDay, int startTime) Sets the daylight saving time start rule to a fixed date within a month. This method is equivalent to:setStartRule(startMonth, startDay, 0, startTime)- Parameters:
startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts.startTime- The daylight saving time starting time in local wall clock time, which is local standard time in this case. See the class description for the special cases of this parameter.- Throws:
IllegalArgumentException- if thestartMonth,startDayOfMonth, orstartTimeparameters are out of range- Since:
- 1.2
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setStartRule
public void setStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime, boolean after) Sets the daylight saving time start rule to a weekday before or after the given date within a month, e.g., the first Monday on or after the 8th.- Parameters:
startMonth- The daylight saving time starting month. Month is aMONTHfield value (0-based. e.g., 0 for January).startDay- The day of the month on which the daylight saving time starts.startDayOfWeek- The daylight saving time starting day-of-week.startTime- The daylight saving time starting time in local wall clock time, which is local standard time in this case.after- If true, this rule selects the firstdayOfWeekon or afterdayOfMonth. If false, this rule selects the lastdayOfWeekon or beforedayOfMonth.- Throws:
IllegalArgumentException- if thestartMonth,startDay,startDayOfWeek, orstartTimeparameters are out of range- Since:
- 1.2
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setEndRule
public void setEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime) Sets the daylight saving time end rule. For example, if daylight saving time ends on the last Sunday in October at 2 am in wall clock time, you can set the end rule by calling:setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);- Parameters:
endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends. See the class description for the special cases of this parameter.endDayOfWeek- The daylight saving time ending day-of-week. See the class description for the special cases of this parameter.endTime- The daylight saving ending time in local wall clock time, (in milliseconds within the day) which is local daylight time in this case.- Throws:
IllegalArgumentException- if theendMonth,endDay,endDayOfWeek, orendTimeparameters are out of range
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setEndRule
public void setEndRule(int endMonth, int endDay, int endTime) Sets the daylight saving time end rule to a fixed date within a month. This method is equivalent to:setEndRule(endMonth, endDay, 0, endTime)- Parameters:
endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends.endTime- The daylight saving ending time in local wall clock time, (in milliseconds within the day) which is local daylight time in this case.- Throws:
IllegalArgumentException- theendMonth,endDay, orendTimeparameters are out of range- Since:
- 1.2
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setEndRule
public void setEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime, boolean after) Sets the daylight saving time end rule to a weekday before or after the given date within a month, e.g., the first Monday on or after the 8th.- Parameters:
endMonth- The daylight saving time ending month. Month is aMONTHfield value (0-based. e.g., 9 for October).endDay- The day of the month on which the daylight saving time ends.endDayOfWeek- The daylight saving time ending day-of-week.endTime- The daylight saving ending time in local wall clock time, (in milliseconds within the day) which is local daylight time in this case.after- If true, this rule selects the firstendDayOfWeekon or afterendDay. If false, this rule selects the lastendDayOfWeekon or beforeendDayof the month.- Throws:
IllegalArgumentException- theendMonth,endDay,endDayOfWeek, orendTimeparameters are out of range- Since:
- 1.2
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getOffset
public int getOffset(long date) Returns the offset of this time zone from UTC at the given time. If daylight saving time is in effect at the given time, the offset value is adjusted with the amount of daylight saving. -
getOffset
public int getOffset(int era, int year, int month, int day, int dayOfWeek, int millis) Returns the difference in milliseconds between local time and UTC, taking into account both the raw offset and the effect of daylight saving, for the specified date and time. This method assumes that the start and end month are distinct. It also uses a defaultGregorianCalendarobject as its underlying calendar, such as for determining leap years. Do not use the result of this method with a calendar other than a defaultGregorianCalendar.Note: In general, clients should use
Calendar.get(ZONE_OFFSET) + Calendar.get(DST_OFFSET)instead of calling this method.- Specified by:
getOffsetin classTimeZone- Parameters:
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.millis- The milliseconds in day in standard local time.- Returns:
- The milliseconds to add to UTC to get local time.
- Throws:
IllegalArgumentException- theera,month,day,dayOfWeek, ormillisparameters are out of range- See Also:
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getRawOffset
public int getRawOffset()Gets the GMT offset for this time zone.- Specified by:
getRawOffsetin classTimeZone- Returns:
- the GMT offset value in milliseconds
- See Also:
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setRawOffset
public void setRawOffset(int offsetMillis) Sets the base time zone offset to GMT. This is the offset to add to UTC to get local time.- Specified by:
setRawOffsetin classTimeZone- Parameters:
offsetMillis- the given base time zone offset to GMT.- See Also:
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setDSTSavings
public void setDSTSavings(int millisSavedDuringDST) Sets the amount of time in milliseconds that the clock is advanced during daylight saving time.- Parameters:
millisSavedDuringDST- the number of milliseconds the time is advanced with respect to standard time when the daylight saving time rules are in effect. A positive number, typically one hour (3600000).- Since:
- 1.2
- See Also:
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getDSTSavings
public int getDSTSavings()Returns the amount of time in milliseconds that the clock is advanced during daylight saving time.- Overrides:
getDSTSavingsin classTimeZone- Returns:
- the number of milliseconds the time is advanced with respect to standard time when the daylight saving rules are in effect, or 0 (zero) if this time zone doesn't observe daylight saving time.
- Since:
- 1.2
- See Also:
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useDaylightTime
public boolean useDaylightTime()Queries if this time zone uses daylight saving time.- Specified by:
useDaylightTimein classTimeZone- Returns:
- true if this time zone uses daylight saving time; false otherwise.
- See Also:
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observesDaylightTime
public boolean observesDaylightTime()Returnstrueif thisSimpleTimeZoneobserves Daylight Saving Time. This method is equivalent touseDaylightTime().- Overrides:
observesDaylightTimein classTimeZone- Returns:
trueif thisSimpleTimeZoneobserves Daylight Saving Time;falseotherwise.- Since:
- 1.7
- See Also:
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inDaylightTime
Queries if the given date is in daylight saving time.- Specified by:
inDaylightTimein classTimeZone- Implementation Requirements:
- The default implementation throws a
NullPointerExceptionifdateisnull - Parameters:
date- the given Date.- Returns:
- true if daylight saving time is in effective at the given date; false otherwise.
- Throws:
NullPointerException- This method may throw aNullPointerExceptionifdateisnull
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clone
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hashCode
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equals
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hasSameRules
Returnstrueif this zone has the same rules and offset as another zone.- Overrides:
hasSameRulesin classTimeZone- Parameters:
other- the TimeZone object to be compared with- Returns:
trueif the given zone is a SimpleTimeZone and has the same rules and offset as this one- Since:
- 1.2
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toString
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