Wrong “week of year” in Android

Question

The number of "week of year" returned from a Date is wrong.

This is my code:

Calendar c = Calendar.getInstance();
c.setTime(my_date);
int num_week = c.get(Calendar.WEEK_OF_YEAR);

If my_date (type Date) is 01/01/2011, I supposed that "week of year" is 1. But it returned 52.

I try to test with these methods but I don't obtain anything:

c.setFirstDayOfWeek(6);
c.setMinimalDaysInFirstWeek(1)

If It's interesting, I'm from Spain, and our week begin on Monday.

Have I to do anything for obtain right results?

Thanks!

Answer 1

This may be Android/Harmony-specific. For example, this works for me with desktop Java:

import java.util.*;

public class Test {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(2011, 0, 1, 0, 0, 0);
        System.out.println(calendar.get(Calendar.WEEK_OF_YEAR)); // Prints 52
        calendar.setMinimalDaysInFirstWeek(1);
        System.out.println(calendar.get(Calendar.WEEK_OF_YEAR)); // Prints 1
    }
}

Can you confirm that the exact same code (modulo logging options) logs 52 twice on Android?

Answer 2

Here you can view the reference by oracle

https://docs.oracle.com/javase/7/docs/api/java/util/GregorianCalendar.html

And I have placed a quick solution to find the week count of current day. You can alter and optimize as your way. Also set according to your convenient GMT value

public static int getWeeksOfMonth() {

    DATESTATUS = false;
    VALUESTATUS = false;
    int weekCount;
    WEEK_OF_MONTH= -1;

    // get the supported ids for GMT+04:00 (Pacific Standard Time)
    String[] ids = getAvailableIDs(4 * 60 * 60 * 1000);
    // if no ids were returned, something is wrong. get out.
    if (ids.length == 0)
        return WEEK_OF_MONTH;

    // create a Pacific Standard Time time zone
    SimpleTimeZone pdt = new SimpleTimeZone(4 * 60 * 60 * 1000, ids[0]);

    // create a GregorianCalendar with the Pacific Daylight time zone
    // and the current date and time
    Calendar calendar = new GregorianCalendar(pdt);
    Date trialTime = new Date();
    calendar.setTime(trialTime);

    weekCount = calendar.get(Calendar.WEEK_OF_YEAR);

    return recursiveWeekCountCheck(calendar, weekCount);
}

private static int recursiveWeekCountCheck(Calendar calendar, int weekCount) {
    if (calendar.get(Calendar.MONTH) == Calendar.DECEMBER && weekCount == 1) {
        DATESTATUS = true;
        calendar.add(Calendar.DAY_OF_MONTH, -1);
        weekCount = calendar.get(Calendar.WEEK_OF_YEAR);
        recursiveWeekCountCheck(calendar, weekCount);
    }
    if (!VALUESTATUS){
        VALUESTATUS = true;
        if (DATESTATUS) {
            weekCount++;
            WEEK_OF_MONTH = weekCount;
        } else {
            WEEK_OF_MONTH = weekCount;
        }
    }
    return WEEK_OF_MONTH;
}

At the end just call the method getWeeksOfMonth();