Name: gsC80088 Date: 02/04/99


There is a defect in the calculations of
DAY_OF_WEEK_IN_MONTH in the Calendar object.
This was apparently introduced in 1.1.6 (as
1.1.5 worked correctly). When setting the
Nth day (i.e. 3rd Friday, 2nd Tuesday), Calendar
always returns the 1st of the month. Defect
can be reproduced using the sample code on
pages 250-251 of "The Java Class Libraries
Second Edition, Volume 1", by Patrick Chan, et.
al. published by Addison Wesley. Code is
reproduced below:

---------
import java.util.*;
import java.text.*;

class CalTest {
// Prints the date of the n'th dayOfWeek in month, year.
static void printDate(int n,int dayOfWeek,int month,int year) {
DateFormat formatter = new SimpleDateFormat("MMM dd yyyy");
Calendar cal = Calendar.getInstance();

cal.clear();
cal.set(Calendar.DAY_OF_WEEK_IN_MONTH,n);
cal.set(Calendar.DAY_OF_WEEK,dayOfWeek);
cal.set(Calendar.MONTH,month);
cal.set(Calendar.YEAR,year);
System.out.println(formatter.format(cal.getTime()));
}

public static void main(String[] args) {
printDate(1,Calendar.SUNDAY,Calendar.JANUARY,1997); // Jan 05 1997
printDate(4,Calendar.SUNDAY,Calendar.JANUARY,1997); // Jan 26 1997
printDate(8,Calendar.SUNDAY,Calendar.JANUARY,1997); // Feb 23 1997

printDate(-1,Calendar.SUNDAY,Calendar.JANUARY,1997); // Jan 26 1997
printDate(-4,Calendar.SUNDAY,Calendar.JANUARY,1997); // Jan 05 1997
printDate(-8,Calendar.SUNDAY,Calendar.JANUARY,1997); // Dec 08 1996
}
}
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Please note that this feature is very useful for
calculating holidays for use with financial software.
(Review ID: 40612)
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