Name: avC70361 Date: 07/27/98



  The java.util.SimpleTimeZone.useDaylightTime() works wrong. It checks only
if both end and start rule have been set and doesn't check if DSTSaving is
equal to 0. So the zone with the defined rules and zero DSTSaving is considered
to use DST. However, as follows from the evaluation of the bug 4154651,
The time zones with zero DSTSaving should be treated as not using DST.

There is also the doc bug 4160708 filed against unclear specs. Please see it for
more details.

Here is a test demonstrating the bug
-------------------UseDaylightTimeTest.java--------------------
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.SimpleTimeZone;

public class UseDaylightTimeTest {
  public static void main(String[] args) {
    SimpleTimeZone stz = new SimpleTimeZone(
      60 * 60 * 1000,
      "MyTimeZone",
      Calendar.JANUARY, 1, 0, 0,
      Calendar.APRIL, 1, 0, 0,
      0
    );

    Calendar calendar = new GregorianCalendar(stz);

    // setting a date during DST period
    calendar.set(Calendar.YEAR, 1998);
    calendar.set(Calendar.MONTH, Calendar.MARCH);
    calendar.set(Calendar.DATE, 1);

    Date duringDST = calendar.getTime();

    // setting a date beyond DST
    calendar.set(Calendar.YEAR, 1998);
    calendar.set(Calendar.MONTH, Calendar.JUNE);
    calendar.set(Calendar.DATE, 1);

    Date beyondDST = calendar.getTime();

    if (stz.useDaylightTime() && !stz.inDaylightTime(duringDST)) {
      System.out.println(
        "time zone = " + stz + "\n" +
        "date = " + duringDST + "\n" +
        "Failed: inDaylightTime(date) returns false for a date during DST and a
zone using Daylight time"
      );
    } else {
      System.out.println("passed");
    }
  }
}
------The test output---------
> java UseDaylightTimeTest
time zone =
java.util.SimpleTimeZone[id=MyTimeZone,offset=3600000,dstSavings=0,useDaylight=t
rue,startYear=0,startMode=1,startMonth=0,startDay=1,startDayOfWeek=0,startTime=0
,endMode=1,endMonth=3,endDay=1,endDayOfWeek=0,endTime=0]
date = Sun Mar 01 14:43:39 GMT+03:00 1998
Failed: inDaylightTime(date) returns false for a date during DST and a zone
using Daylight time

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