how to get MONTHS, DAYS and weeks (android datepicker)

Question

UPDATE

I am creating a pregnancy due date countdown, so I use android.widget.DatePicker as a tool to set the due date.

For example:

• the set due date is Jan. 9 2015
• the date now is Nov. 9 2014
• so the left months, days and weeks is 2 months, 62 days and 8weeks

So far i can only display the set due date.

Question: How to get the exact months weeks and days left when the user set the due date.

UPDATE CODE

Here's the code:

private TextView txtResultDueDate ;
       private DatePicker datePicker;
       private Calendar calendar;
       private int year;
       private int month;
       private int day;

       static final int DATE_DIALOG_ID = 999;

       @Override
       protected void onCreate(Bundle savedInstanceState) {

          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_profile);

           txtResultDueDate = (TextView) findViewById(R.id.txtDue);
           btnChangeDate = (Button)findViewById(R.id.button1);

            calendar = Calendar.getInstance();
            year = calendar.get(Calendar.YEAR);
            month = calendar.get(Calendar.MONTH);
            day = calendar.get(Calendar.DAY_OF_MONTH);
            showDate(year, month+1, day);

       @SuppressWarnings("deprecation")
       public void setDate(View view) {
          showDialog(999);
          Toast.makeText(getApplicationContext(), "ca", Toast.LENGTH_SHORT)
          .show();
       }

       @Override
       protected Dialog onCreateDialog(int id) {
       // TODO Auto-generated method stub
          if (id == 999) {
             return new DatePickerDialog(this, myDateListener, year, month, day);
           }
          return null;
       }

       private DatePickerDialog.OnDateSetListener myDateListener
       = new DatePickerDialog.OnDateSetListener() {

       @Override
       public void onDateSet(DatePicker arg0, int year, int month, int day) {
     Chronology chrono = GregorianChronology.getInstance();  
       DateTime end = new DateTime(arg0.getYear(), arg0.getMonth(), arg0.getDayOfMonth(), 0, 0, chrono);

       DateTime current = new DateTime();
       Interval interval = new Interval(current.toInstant(), end.toInstant());
       Period duePeriod = interval.toPeriod();
       showDate(duePeriod.getYears(), duePeriod.getMonths(), duePeriod.getDays());


       }
       };

       private void showDate(int year, int month, int day) {
          txtResultDueDate.setText(new StringBuilder().append(day).append("/")
          .append(month).append("/").append(year));
       }

This is the error that I encounter when I set the due date using DatePicker:

FATAL EXCEPTION: main

java.lang.IllegalArgumentException: The end instant must be greater orequal to the start

at org.joda.time.base.Abstraction.checkInterval(AbstractInterval.java.63)

at org.joda.time.base.BaseInterval(BaseInterval.java:94)

at org.joda.time.Interval.(Interval.java.122)

at com.date.androin.Profile$1.onDataset(Profile.java:168)

at android.app.DatePickerDialog.tryNotifyDataSet(DatePickerDialog.java.148)

at android.app.DatePickerDialog.onClick(DatePickerDialog.java.116)

at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)

at android.os.Handler.dispatchMessage(Handler.java:99)

at android.os.Looper.loop(Looper.java:137)

at android.app.ActivityThread.main(ActivityThread.java:5103)

at java.lang.reflect.Method.invokeNative(Native Method)

at java.lang.reflect.Method.invoke(Method.java:511)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)

at dalvik.system.NativeStrat.main(Native Method)

Answer 1

There is a library Joda Time. It is better the Date API provided by Java

Joda Time has a concept of time Interval:

Interval interval = new Interval(oldTime, new Instant());

Yes, you can use joda lib with android DatePicker

Chronology chrono = GregorianChronology.getInstance();
// end datetime
DateTime end = new DateTime(datePicker.getYear(), datePicker.getMonth(),       datePicker.getDayOfMonth(), 0, 0 ,chrono);

// current datetime
DateTime current = new DateTime();

Then instantiate Interval with start and end datetime

Interval interval = new Interval(current.toInstant(), end.toInstant()); then use the Interval api to get the Period from which you can extract the difference of months/days/weeks

Period duePeriod = interval.toPeriod();

// get difference in months

duePeriod.getMonths();

// get difference in weeks

duePeriod.getWeeks();

PLease refer the below Javadoc of Period for complete list of API http://joda-time.sourceforge.net/apidocs/org/joda/time/Period.html

For Android, in your case add the above code into your DatePicker onDateSet listener. finally the listener method would like this,

@Override
public void onDateSet(DatePicker arg0, int year, int month, int day) {
   // TODO Auto-generated method stub
   Chronology chrono = GregorianChronology.getInstance(); 
   // end datetime 
   DateTime end = new DateTime(arg0.getYear(), arg0.getMonth(), arg0.getDayOfMonth(), 0, 0, chrono);
   // current datetime 
   DateTime current = new DateTime();
   Interval interval = new Interval(current.toInstant(), end.toInstant());
   Period duePeriod = interval.toPeriod();
   showDate(duePeriod.getYears(), duePeriod.getMonths(), duePeriod.getDays());
}

Answer 2

//somewhere in your code, init part
Calendar then = setDate(9, 0, 2015);//9 january 2015
Calendar c = Calendar.getInstance();
Calendar now = setDate(c.get(Calendar.DAY_OF_MONTH), c.get(Calendar.MONTH), c.get(Calendar.YEAR));
String leftDays = getLeftDays(then, now);//your result

//method setting days months years - we ignore hours and minutes
private String getLeftDays(Calendar then, Calendar now) {
    long leftMilis = then.getTimeInMillis() - now.getTimeInMillis();
    int seconds = (int) (leftMilis / 1000);
    Log.d(TAG, "seconds:" + seconds);
    int minutes = seconds / 60;
    Log.d(TAG, "minutes:" + minutes);
    int hours = minutes / 60;
    Log.d(TAG, "hours:" + hours);
    int days = hours / 24;
    Log.d(TAG, "days:" + days);
    int weeks = days / 7;
    Log.d(TAG, "weeks:" + weeks);

    //months.. another way calculating data due not equal amount of days per month
    Calendar temp = ((Calendar) then.clone());
    temp.add(Calendar.MONTH, -now.get(Calendar.MONTH));
    int months = temp.get(Calendar.MONTH);
    Log.d(TAG, "months:" + months);

    StringBuilder sb = new StringBuilder();
    String format = "%d months, %d days, %d weeks";
    String formatStr = String.format(format, months, days, weeks);

    String result = sb.append(formatStr).toString();
    Log.d(TAG, sb.toString());
    return result;
}

private Calendar setDate(int day, int month, int year) {
    Calendar c = Calendar.getInstance();
    c.set(Calendar.DAY_OF_MONTH, day);
    c.set(Calendar.MONTH, month);
    c.set(Calendar.YEAR, year);
    c.set(Calendar.HOUR, 0);
    c.set(Calendar.MINUTE, 0);
    c.set(Calendar.SECOND, 0);
    Log.d(TAG, c.getTime().toString());
    return c;
}

Answer 3

Calendar c = calendar.getInstance();

and DatePickerDialog d

@Override public void onDateSet(DatePicker view,int Year,int mont of Year,int day of month){

Toast

c.get(Calendar.Year),c.get(Calendar.Month),c.get(Calendar.Day_of_Month);

d.show

Answer 4

this code is to find week from selected date,it's proper work.
Calendar date1 = Calendar.getInstance();
        Calendar date2 = Calendar.getInstance();

        date1.clear();
        date1.set(Integer.parseInt(selected_year), Integer.parseInt(selected_month), Integer.parseInt(selected_date)); // set date 1 (yyyy,mm,dd)
        System.out.println("Selected Date==>>" + date1);

        date2.clear();
        date2.set(Integer.parseInt(current_year), Integer.parseInt(current_month), Integer.parseInt(current_date));
        System.out.println("Current Date==>>" + date2);

        long diff = date2.getTimeInMillis() - date1.getTimeInMillis();
        float dayCount = (float) diff / (24 * 60 * 60 * 1000);
        week = (int) (dayCount / 7);

        if (week <= 0) {
            Toast.makeText(this, "Sry System Error", Toast.LENGTH_SHORT).show();
            System.out.println("Week==>>" + week);
            test = false;
        } else {
            Toast.makeText(this, "Done", Toast.LENGTH_SHORT).show();
            System.out.println("Week==>>" + week);
            test = true;
        }