Android DatePicker片段返回日期前一個月

好吧，這是離奇的。我有一個非常簡單的DatePicker對話框。問題是無論我選擇什麼日期，返回的價值恰好是選定日期的前一個月。這裏是我的代碼：Android DatePicker片段返回日期前一個月

活動

btnEventDate.setOnClickListener(new View.OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     DialogFragment newFragment = new DatePickerFragment(); 
     newFragment.show(getSupportFragmentManager(), "datePicker"); 
    } 
}); 

@Override 
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { 
    DateTime dt = new DateTime(year, monthOfYear, dayOfMonth, 0, 0, 0, 0); 
    Log.d(Constants.TAG, "dt: " + dt.toString()); 
    Log.d(Constants.TAG, "str: " + dateHandler.convertDateToYYYY_MM_DDString(dt)); 
}

DatePickerFragment

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener { 

    @Override 
    public Dialog onCreateDialog(Bundle savedInstanceState) { 
     // Use the current date as the default date in the picker 
     final Calendar c = Calendar.getInstance(); 
     int year = c.get(Calendar.YEAR); 
     int month = c.get(Calendar.MONTH); 
     int day = c.get(Calendar.DAY_OF_MONTH); 

     return new DatePickerDialog(getActivity(), (OnDateSetListener)getActivity(), year, month, day); 
    } 

    public void onDateSet(DatePicker view, int year, int month, int day) {} 
}

對話框出現時，它顯然是設置爲今天的日期。再說說我選擇2015年10月12日，日誌輸出表明這一點：