UDate TimeZoneRegressionTest::findTransitionStepwise(const SimpleTimeZone& tz, UDate min, UDate max) {
    UErrorCode status = U_ZERO_ERROR;
    UBool startsInDST = tz.inDaylightTime(min, status);
    if (failure(status, "SimpleTimeZone::inDaylightTime")) return 0;
    while (min < max) {
        if (tz.inDaylightTime(min, status) != startsInDST) {
            return min;
        }
        if (failure(status, "SimpleTimeZone::inDaylightTime")) return 0;
        min += (UDate)24*60*60*1000; // one day
    }
    return 0;
}
UDate TimeZoneRegressionTest::findTransitionBinary(const SimpleTimeZone& tz, UDate min, UDate max) {
    UErrorCode status = U_ZERO_ERROR;
    UBool startsInDST = tz.inDaylightTime(min, status);
    if (failure(status, "SimpleTimeZone::inDaylightTime")) return 0;
    if (tz.inDaylightTime(max, status) == startsInDST) {
        logln((UnicodeString)"Error: inDaylightTime() != " + ((!startsInDST)?"TRUE":"FALSE"));
        return 0;
    }
    if (failure(status, "SimpleTimeZone::inDaylightTime")) return 0;
    while ((max - min) > 100) { // Min accuracy in ms
        UDate mid = (min + max) / 2;
        if (tz.inDaylightTime(mid, status) == startsInDST) {
            min = mid;
        } else {
            max = mid;
        }
        if (failure(status, "SimpleTimeZone::inDaylightTime")) return 0;
    }
    return (min + max) / 2;
}
// {sfb} will this work using a Calendar?
void TimeZoneRegressionTest:: Test4073215() 
{
    UErrorCode status = U_ZERO_ERROR;
    UnicodeString str, str2;
    SimpleTimeZone *z = new SimpleTimeZone(0, "GMT");
    if (z->useDaylightTime())
        errln("Fail: Fix test to start with non-DST zone");
    z->setStartRule(UCAL_FEBRUARY, 1, UCAL_SUNDAY, 0, status);
    failure(status, "z->setStartRule()");
    z->setEndRule(UCAL_MARCH, -1, UCAL_SUNDAY, 0, status);
    failure(status, "z->setStartRule()");
    if (!z->useDaylightTime())
        errln("Fail: DST not active");

    GregorianCalendar cal(1997, UCAL_JANUARY, 31, status);
    if(U_FAILURE(status)) {
      dataerrln("Error creating calendar %s", u_errorName(status));
      return;
    }
    failure(status, "new GregorianCalendar");
    cal.adoptTimeZone(z);

    SimpleDateFormat sdf((UnicodeString)"E d MMM yyyy G HH:mm", status); 
    if(U_FAILURE(status)) {
      dataerrln("Error creating date format %s", u_errorName(status));
      return;
    }
    sdf.setCalendar(cal); 
    failure(status, "new SimpleDateFormat");

    UDate jan31, mar1, mar31;

    UBool indt = z->inDaylightTime(jan31=cal.getTime(status), status);
    failure(status, "inDaylightTime or getTime call on Jan 31");
    if (indt) {
        errln("Fail: Jan 31 inDaylightTime=TRUE, exp FALSE");
    }
    cal.set(1997, UCAL_MARCH, 1);
    indt = z->inDaylightTime(mar1=cal.getTime(status), status);
    failure(status, "inDaylightTime or getTime call on Mar 1");
    if (!indt) {
        UnicodeString str;
        sdf.format(cal.getTime(status), str);
        failure(status, "getTime");
        errln((UnicodeString)"Fail: " + str + " inDaylightTime=FALSE, exp TRUE");
    }
    cal.set(1997, UCAL_MARCH, 31);
    indt = z->inDaylightTime(mar31=cal.getTime(status), status);
    failure(status, "inDaylightTime or getTime call on Mar 31");
    if (indt) {
        errln("Fail: Mar 31 inDaylightTime=TRUE, exp FALSE");
    }

    /*
    cal.set(1997, Calendar::DECEMBER, 31);
    UDate dec31 = cal.getTime(status);
    failure(status, "getTime");
    UDate trans = findTransitionStepwise(*z, jan31, dec31);
    logln((UnicodeString)"Stepwise from " +
          sdf.format(jan31, str.remove()) + "; transition at " +
          (trans?sdf.format(trans, str2.remove()):(UnicodeString)"NONE"));
    trans = findTransitionStepwise(*z, mar1, dec31);
    logln((UnicodeString)"Stepwise from " +
          sdf.format(mar1, str.remove()) + "; transition at " +
          (trans?sdf.format(trans, str2.remove()):(UnicodeString)"NONE"));
    trans = findTransitionStepwise(*z, mar31, dec31);
    logln((UnicodeString)"Stepwise from " +
          sdf.format(mar31, str.remove()) + "; transition at " +
          (trans?sdf.format(trans, str2.remove()):(UnicodeString)"NONE"));
    */
}