Package java.util

Class SimpleTimeZone

java.lang.Object
java.util.TimeZone
java.util.SimpleTimeZone
All Implemented Interfaces:
Serializable, Cloneable
public class SimpleTimeZone
extends TimeZone
SimpleTimeZone is a concrete subclass of TimeZone that represents a time zone for use with a Gregorian calendar. This class does not handle historical changes.

Use a negative value for dayOfWeekInMonth to indicate that SimpleTimeZone should count from the end of the month backwards. For example, Daylight Savings Time ends at the last (dayOfWeekInMonth = -1) Sunday in October, at 2 AM in standard time.

See Also:
Calendar, GregorianCalendar, TimeZone, Serialized Form

  • Field Summary

    Fields
    Modifier and Type Field Description
    static int STANDARD_TIME
    The constant for representing a start or end time in standard local time mode, based on timezone's raw offset from GMT; does not include Daylight savings.
    static int UTC_TIME
    The constant for representing a start or end time in GMT time mode.
    static int WALL_TIME
    The constant for representing a start or end time in local wall clock time mode, based on timezone's adjusted offset from GMT; includes Daylight savings.

    Fields inherited from class java.util.TimeZone

    LONG, SHORT

  • Constructor Summary

    Constructors
    Constructor Description
    SimpleTimeZone​(int offset, String name)
    Constructs a SimpleTimeZone with the given base time zone offset from GMT and time zone ID.
    SimpleTimeZone​(int offset, String name, 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 times to start and end the daylight savings time.
    SimpleTimeZone​(int offset, String name, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime, int daylightSavings)
    Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, times to start and end the daylight savings time, and the daylight savings time difference in milliseconds.
    SimpleTimeZone​(int offset, String name, int startMonth, int startDay, int startDayOfWeek, int startTime, int startTimeMode, int endMonth, int endDay, int endDayOfWeek, int endTime, int endTimeMode, int daylightSavings)
    Construct a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, times to start and end the daylight savings time including a mode specifier, the daylight savings time difference in milliseconds.

  • Method Summary

    Modifier and Type Method Description
    Object clone()
    Returns a new SimpleTimeZone with the same ID, rawOffset and daylight savings time rules as this SimpleTimeZone.
    boolean equals​(Object object)
    Compares the specified object to this SimpleTimeZone and returns whether they are equal.
    int getDSTSavings()
    Returns the latest daylight savings in milliseconds for this time zone, relative to this time zone's regular UTC offset (as returned by TimeZone.getRawOffset()).
    int getOffset​(int era, int year, int month, int day, int dayOfWeek, int time)
    Returns this time zone's offset in milliseconds from UTC at the specified date and time.
    int getOffset​(long time)
    Returns the offset in milliseconds from UTC for this time zone at time.
    int getRawOffset()
    Returns the offset in milliseconds from UTC of this time zone's standard time.
    int hashCode()
    Returns an integer hash code for the receiver.
    boolean hasSameRules​(TimeZone zone)
    Returns true if timeZone has the same rules as this time zone.
    boolean inDaylightTime​(Date time)
    Returns true if time is in a daylight savings time period for this time zone.
    void setDSTSavings​(int milliseconds)
    Sets the daylight savings offset in milliseconds for this SimpleTimeZone.
    void setEndRule​(int month, int dayOfMonth, int time)
    Sets the rule which specifies the end of daylight savings time.
    void setEndRule​(int month, int day, int dayOfWeek, int time)
    Sets the rule which specifies the end of daylight savings time.
    void setEndRule​(int month, int day, int dayOfWeek, int time, boolean after)
    Sets the rule which specifies the end of daylight savings time.
    void setRawOffset​(int offset)
    Sets the offset for standard time from GMT for this SimpleTimeZone.
    void setStartRule​(int month, int dayOfMonth, int time)
    Sets the rule which specifies the start of daylight savings time.
    void setStartRule​(int month, int day, int dayOfWeek, int time)
    Sets the rule which specifies the start of daylight savings time.
    void setStartRule​(int month, int day, int dayOfWeek, int time, boolean after)
    Sets the rule which specifies the start of daylight savings time.
    void setStartYear​(int year)
    Sets the starting year for daylight savings time in this SimpleTimeZone.
    String toString()
    Returns the string representation of this SimpleTimeZone.
    boolean useDaylightTime()
    Returns true if this time zone has a future transition to or from daylight savings time.

    Methods inherited from class java.util.TimeZone

    getAvailableIDs, getAvailableIDs, getDefault, getDisplayName, getDisplayName, getDisplayName, getDisplayName, getID, getTimeZone, setDefault, setID

    Methods inherited from class java.lang.Object

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

  • Field Details

    • UTC_TIME

      public static final int UTC_TIME
      The constant for representing a start or end time in GMT time mode.
      See Also:
      Constant Field Values

    • STANDARD_TIME

      public static final int STANDARD_TIME
      The constant for representing a start or end time in standard local time mode, based on timezone's raw offset from GMT; does not include Daylight savings.
      See Also:
      Constant Field Values

    • WALL_TIME

      public static final int WALL_TIME
      The constant for representing a start or end time in local wall clock time mode, based on timezone's adjusted offset from GMT; includes Daylight savings.
      See Also:
      Constant Field Values

  • Constructor Details

    • SimpleTimeZone

      public SimpleTimeZone​(int offset, String name)
      Constructs a SimpleTimeZone with the given base time zone offset from GMT and time zone ID. Timezone IDs can be obtained from TimeZone.getAvailableIDs. Normally you should use TimeZone.getDefault to construct a TimeZone.
      Parameters:
      offset - the given base time zone offset to GMT.
      name - the time zone ID which is obtained from TimeZone.getAvailableIDs.

    • SimpleTimeZone

      public SimpleTimeZone​(int offset, String name, 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 times to start and end the daylight savings time. Timezone IDs can be obtained from TimeZone.getAvailableIDs. Normally you should use TimeZone.getDefault to create a TimeZone. For a time zone that does not use daylight saving time, do not use this constructor; instead you should use SimpleTimeZone(rawOffset, ID).

      By default, this constructor specifies day-of-week-in-month rules. That is, if the startDay is 1, and the startDayOfWeek is SUNDAY, then this indicates the first Sunday in the startMonth. A startDay of -1 likewise indicates the last Sunday. However, by using negative or zero values for certain parameters, other types of rules can be specified.

      Day of month: To specify an exact day of the month, such as March 1, set startDayOfWeek to zero.

      Day of week after day of month: To specify the first day of the week occurring on or after an exact day of the month, make the day of the week negative. For example, if startDay is 5 and startDayOfWeek is -MONDAY, this indicates the first Monday on or after the 5th day of the startMonth.

      Day of week before day of month: To specify the last day of the week occurring on or before an exact day of the month, make the day of the week and the day of the month negative. For example, if startDay is -21 and startDayOfWeek is -WEDNESDAY, this indicates the last Wednesday on or before the 21st of the startMonth.

      The above examples refer to the startMonth, startDay, and startDayOfWeek; the same applies for the endMonth, endDay, and endDayOfWeek.

      The daylight savings time difference is set to the default value: one hour.

      Parameters:
      offset - the given base time zone offset to GMT.
      name - the time zone ID which is obtained from TimeZone.getAvailableIDs.
      startMonth - the daylight savings starting month. The month indexing is 0-based. eg, 0 for January.
      startDay - the daylight savings starting day-of-week-in-month. Please see the member description for an example.
      startDayOfWeek - the daylight savings starting day-of-week. Please see the member description for an example.
      startTime - the daylight savings starting time in local wall time, which is standard time in this case. Please see the member description for an example.
      endMonth - the daylight savings ending month. The month indexing is 0-based. eg, 0 for January.
      endDay - the daylight savings ending day-of-week-in-month. Please see the member description for an example.
      endDayOfWeek - the daylight savings ending day-of-week. Please see the member description for an example.
      endTime - the daylight savings ending time in local wall time, which is daylight time in this case. Please see the member description for an example.
      Throws:
      IllegalArgumentException - if the month, day, dayOfWeek, or time parameters are out of range for the start or end rule.

    • SimpleTimeZone

      public SimpleTimeZone​(int offset, String name, int startMonth, int startDay, int startDayOfWeek, int startTime, int endMonth, int endDay, int endDayOfWeek, int endTime, int daylightSavings)
      Constructs a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, times to start and end the daylight savings time, and the daylight savings time difference in milliseconds.
      Parameters:
      offset - the given base time zone offset to GMT.
      name - the time zone ID which is obtained from TimeZone.getAvailableIDs.
      startMonth - the daylight savings starting month. Month is 0-based. eg, 0 for January.
      startDay - the daylight savings starting day-of-week-in-month. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      startDayOfWeek - the daylight savings starting day-of-week. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      startTime - The daylight savings starting time in local wall time, which is standard time in this case. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      endMonth - the daylight savings ending month. Month is 0-based. eg, 0 for January.
      endDay - the daylight savings ending day-of-week-in-month. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      endDayOfWeek - the daylight savings ending day-of-week. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      endTime - the daylight savings ending time in local wall time, which is daylight time in this case. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      daylightSavings - the daylight savings time difference in milliseconds.
      Throws:
      IllegalArgumentException - if the month, day, dayOfWeek, or time parameters are out of range for the start or end rule.

    • SimpleTimeZone

      public SimpleTimeZone​(int offset, String name, int startMonth, int startDay, int startDayOfWeek, int startTime, int startTimeMode, int endMonth, int endDay, int endDayOfWeek, int endTime, int endTimeMode, int daylightSavings)
      Construct a SimpleTimeZone with the given base time zone offset from GMT, time zone ID, times to start and end the daylight savings time including a mode specifier, the daylight savings time difference in milliseconds. The mode specifies either WALL_TIME, STANDARD_TIME, or UTC_TIME.
      Parameters:
      offset - the given base time zone offset to GMT.
      name - the time zone ID which is obtained from TimeZone.getAvailableIDs.
      startMonth - the daylight savings starting month. The month indexing is 0-based. eg, 0 for January.
      startDay - the daylight savings starting day-of-week-in-month. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      startDayOfWeek - the daylight savings starting day-of-week. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      startTime - the time of day in milliseconds on which daylight savings time starts, based on the startTimeMode.
      startTimeMode - the mode (UTC, standard, or wall time) of the start time value.
      endDay - the day of the week on which daylight savings time ends.
      endMonth - the daylight savings ending month. The month indexing is 0-based. eg, 0 for January.
      endDayOfWeek - the daylight savings ending day-of-week. Please see the description of SimpleTimeZone(int, String, int, int, int, int, int, int, int, int) for an example.
      endTime - the time of day in milliseconds on which daylight savings time ends, based on the endTimeMode.
      endTimeMode - the mode (UTC, standard, or wall time) of the end time value.
      daylightSavings - the daylight savings time difference in milliseconds.
      Throws:
      IllegalArgumentException - if the month, day, dayOfWeek, or time parameters are out of range for the start or end rule.

  • Method Details

    • clone

      public Object clone()
      Returns a new SimpleTimeZone with the same ID, rawOffset and daylight savings time rules as this SimpleTimeZone.
      Overrides:
      clone in class TimeZone
      Returns:
      a shallow copy of this SimpleTimeZone.
      See Also:
      Cloneable

    • equals

      public boolean equals​(Object object)
      Compares the specified object to this SimpleTimeZone and returns whether they are equal. The object must be an instance of SimpleTimeZone and have the same internal data.
      Overrides:
      equals in class Object
      Parameters:
      object - the object to compare with this object.
      Returns:
      true if the specified object is equal to this SimpleTimeZone, false otherwise.
      See Also:
      hashCode()

    • getDSTSavings

      public int getDSTSavings()
      Description copied from class: TimeZone
      Returns the latest daylight savings in milliseconds for this time zone, relative to this time zone's regular UTC offset (as returned by TimeZone.getRawOffset()).

      This class returns 3600000 (1 hour) for time zones that use daylight savings time and 0 for timezones that do not, leaving it to subclasses to override this method for other daylight savings offsets. (There are time zones, such as Australia/Lord_Howe, that use other values.)

      Note that this method doesn't tell you whether or not to apply the offset: you need to call inDaylightTime for the specific time you're interested in. If this method returns a non-zero offset, that only tells you that this TimeZone sometimes observes daylight savings.

      Note also that this method doesn't necessarily return the value you need to apply to the time you're working with. This value can and does change over time for a given time zone.

      It's highly unlikely that you should ever call this method. You probably want TimeZone.getOffset(long) instead, which tells you the offset for a specific point in time, and takes daylight savings into account for you.

      Overrides:
      getDSTSavings in class TimeZone

    • getOffset

      public int getOffset​(int era, int year, int month, int day, int dayOfWeek, int time)
      Description copied from class: TimeZone
      Returns this time zone's offset in milliseconds from UTC at the specified date and time. The offset includes daylight savings time if the date and time is within the daylight savings time period.

      This method is intended to be used by Calendar to compute Calendar.DST_OFFSET and Calendar.ZONE_OFFSET. Application code should have no reason to call this method directly. Each parameter is interpreted in the same way as the corresponding Calendar field. Refer to Calendar for specific definitions of this method's parameters.

      Specified by:
      getOffset in class TimeZone

    • getOffset

      public int getOffset​(long time)
      Description copied from class: TimeZone
      Returns the offset in milliseconds from UTC for this time zone at time. The offset includes daylight savings time if the specified date is within the daylight savings time period.
      Overrides:
      getOffset in class TimeZone
      Parameters:
      time - the date in milliseconds since January 1, 1970 00:00:00 UTC

    • getRawOffset

      public int getRawOffset()
      Description copied from class: TimeZone
      Returns the offset in milliseconds from UTC of this time zone's standard time.
      Specified by:
      getRawOffset in class TimeZone

    • hashCode

      public int hashCode()
      Returns an integer hash code for the receiver. Objects which are equal return the same value for this method.
      Overrides:
      hashCode in class Object
      Returns:
      the receiver's hash.
      See Also:
      equals(java.lang.Object)

    • hasSameRules

      public boolean hasSameRules​(TimeZone zone)
      Description copied from class: TimeZone
      Returns true if timeZone has the same rules as this time zone.

      The base implementation returns true if both time zones have the same raw offset.

      Overrides:
      hasSameRules in class TimeZone

    • inDaylightTime

      public boolean inDaylightTime​(Date time)
      Description copied from class: TimeZone
      Returns true if time is in a daylight savings time period for this time zone.
      Specified by:
      inDaylightTime in class TimeZone

    • setDSTSavings

      public void setDSTSavings​(int milliseconds)
      Sets the daylight savings offset in milliseconds for this SimpleTimeZone.
      Parameters:
      milliseconds - the daylight savings offset in milliseconds.

    • setEndRule

      public void setEndRule​(int month, int dayOfMonth, int time)
      Sets the rule which specifies the end of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time ends.
      dayOfMonth - the Calendar day of the month on which daylight savings time ends.
      time - the time of day in milliseconds standard time on which daylight savings time ends.

    • setEndRule

      public void setEndRule​(int month, int day, int dayOfWeek, int time)
      Sets the rule which specifies the end of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time ends.
      day - the occurrence of the day of the week on which daylight savings time ends.
      dayOfWeek - the Calendar day of the week on which daylight savings time ends.
      time - the time of day in milliseconds standard time on which daylight savings time ends.

    • setEndRule

      public void setEndRule​(int month, int day, int dayOfWeek, int time, boolean after)
      Sets the rule which specifies the end of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time ends.
      day - the Calendar day of the month.
      dayOfWeek - the Calendar day of the week on which daylight savings time ends.
      time - the time of day in milliseconds on which daylight savings time ends.
      after - selects the day after or before the day of month.

    • setRawOffset

      public void setRawOffset​(int offset)
      Sets the offset for standard time from GMT for this SimpleTimeZone.
      Specified by:
      setRawOffset in class TimeZone
      Parameters:
      offset - the offset from GMT of standard time in milliseconds.

    • setStartRule

      public void setStartRule​(int month, int dayOfMonth, int time)
      Sets the rule which specifies the start of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time starts.
      dayOfMonth - the Calendar day of the month on which daylight savings time starts.
      time - the time of day in milliseconds on which daylight savings time starts.

    • setStartRule

      public void setStartRule​(int month, int day, int dayOfWeek, int time)
      Sets the rule which specifies the start of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time starts.
      day - the occurrence of the day of the week on which daylight savings time starts.
      dayOfWeek - the Calendar day of the week on which daylight savings time starts.
      time - the time of day in milliseconds on which daylight savings time starts.

    • setStartRule

      public void setStartRule​(int month, int day, int dayOfWeek, int time, boolean after)
      Sets the rule which specifies the start of daylight savings time.
      Parameters:
      month - the Calendar month in which daylight savings time starts.
      day - the Calendar day of the month.
      dayOfWeek - the Calendar day of the week on which daylight savings time starts.
      time - the time of day in milliseconds on which daylight savings time starts.
      after - selects the day after or before the day of month.

    • setStartYear

      public void setStartYear​(int year)
      Sets the starting year for daylight savings time in this SimpleTimeZone. Years before this start year will always be in standard time.
      Parameters:
      year - the starting year.

    • toString

      public String toString()
      Returns the string representation of this SimpleTimeZone.
      Overrides:
      toString in class Object
      Returns:
      the string representation of this SimpleTimeZone.

    • useDaylightTime

      public boolean useDaylightTime()
      Description copied from class: TimeZone
      Returns true if this time zone has a future transition to or from daylight savings time.

      Warning: this returns false for time zones like Asia/Kuala_Lumpur that have previously used DST but do not currently. A hypothetical country that has never observed daylight savings before but plans to start next year would return true.

      Warning: this returns true for time zones that use DST, even when it is not active.

      Use TimeZone.inDaylightTime(java.util.Date) to find out whether daylight savings is in effect at a specific time.

      Most applications should not use this method.

      Specified by:
      useDaylightTime in class TimeZone