How to obtain week of year for any given date

[sun sel]

Hi,
I am trying to find a way to obtain the week of the year for any user entered date. but each time the week of the year corresponding to todays date.
Please help.
Thanks,
sunsel

[Peter Kristensson]

Can you post some code please?
/Peter

[John Lee]

It depends on how you define the week of the year. Will the first partial week be counted as first week?
You can calculate Julian date (how many days from January 1 to that day), then use mode(days, 7) function to find out how many weeks passed. Then again, it depends on the definition.

[Marilyn de Queiroz]

If you know the "day" of the year, you can divide by 7.

[Cory Wilkerson]

  
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
class TestDate {
    public static void main(String[] args) {
        try {
            if (args != null & args.length > 0) {
                SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
                Date d = sdf.parse(args[0]);
                Calendar cal = Calendar.getInstance();
                cal.setTime(d);
                System.out.println(cal.get(Calendar.WEEK_OF_YEAR));
            }
        } catch (Exception e){
            e.printStackTrace();
        }
    }
}

Maybe what you're after.
Usage: java TestDate 06/08/1982
[ January 04, 2003: Message edited by: Cory Wilkerson ]

[John Lee]

I am just guessing:
Will it work if you use:
Calender c = new Calender() ;
to create Calender object.

[Nayanjyoti Talukdar]

Hi,
We can create object using:
Calendar cal = new Calendar();
But the problem, we'll be facing here is that we can't use the fields and methods of class GregorianCalendar which has all the important methods of date format.
-------------
Nayan.

[Jim Yingst]

Perhaps you guys should try compiling

  Calendar c = new Calendar();

to see what happens.

[John Lee]

Hi:

but each time the week of the year corresponding to todays date.

I thought this is the problem.

[Nayanjyoti Talukdar]

Hi,
I'm sorry. I missed out...
Calendar is an abstract class, so we can't instantiate that.
-------------
Nayan.

[Nayanjyoti Talukdar]

Hi,
Just check this out..

//setting the yy/mm/dd
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR,1994);
c.set(Calendar.MONTH,5);
c.set(Calendar.DAY_OF_MONTH,3);
//get the values here
int weekOfYear = c.get(Calendar.WEEK_OF_YEAR);

---------
Nayan

[John Lee]

Hi:

//setting the yy/mm/dd
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR,1994);
c.set(Calendar.MONTH,5);
c.set(Calendar.DAY_OF_MONTH,3);
//get the values here
int weekOfYear = c.get(Calendar.WEEK_OF_YEAR);

cal.setTime(d);     

Now compare these two codes, could this be the reason?

[Rene Larsen]

NOTE...
when you are using 'c.set(Calendar.MONTH, 5);' you need to subtract 1 from the month, because the first month has the value 0.
Rene
[ January 08, 2003: Message edited by: Rene Larsen ]