//It may help you. 

public class SelectDateFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

        Calendar calendar;

        @NonNull
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {

            calendar = Calendar.getInstance();
            calendar.setTimeZone(TimeZone.getTimeZone("UTC"));


            int yy = calendar.get(Calendar.YEAR);
            int mm = calendar.get(Calendar.MONTH);
            int dd = calendar.get(Calendar.DAY_OF_MONTH);
            today = calendar.getTime();

            return new DatePickerDialog(getActivity(), this, yy, mm, dd);
        }

        public void onDateSet(DatePicker view, int yy, int mm, int dd) {
            System.out.print("Current_time::::"+calendar.getTime());
            populateSetDate(yy, mm, dd);
        }

        public void populateSetDate(int year, int month, int day) {

            calendar.set(Calendar.YEAR, year);
            calendar.set(Calendar.MONTH, month);
            calendar.set(Calendar.DAY_OF_MONTH, day);
            pick = calendar.getTime();


                @SuppressLint("SimpleDateFormat") SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
                String formattedDate = df.format(calendar.getTime());

                txtview.setText(formattedDate);





        }

    }