how to disable specific dates in calendar using android dialog datepicker

Question

i want to disable specific dates in calendar.I am using android dialog datepicker.can any one help me please.thank you in advance.i have tried alot but did not find correct solution

am using this for disable aleredy booked slots

my code:

 public class CalendarActivity extends AppCompatActivity implements
            View.OnClickListener {

        Button btnDatePicker, btnTimePicker;
        EditText txtDate, txtTime;
        private int mYear, mMonth, mDay, mHour, mMinute;
        int day=24;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.calendar_layout);
            Toast.makeText(this,String.valueOf(System.currentTimeMillis()), Toast.LENGTH_LONG).show();
            btnDatePicker=(Button)findViewById(R.id.btn_date);
            btnTimePicker=(Button)findViewById(R.id.btn_time);
            txtDate=(EditText)findViewById(R.id.in_date);
            txtTime=(EditText)findViewById(R.id.in_time);

            btnDatePicker.setOnClickListener(this);
            btnTimePicker.setOnClickListener(this);

        }

        @Override
        public void onClick(View v) {

            if (v == btnDatePicker) {

                // Get Current Date
                final Calendar c = Calendar.getInstance();
                mYear = c.get(Calendar.YEAR);
                mMonth = c.get(Calendar.MONTH);
                mDay = c.get(Calendar.DAY_OF_MONTH);


                DatePickerDialog datePickerDialog = new DatePickerDialog(this,
                        new DatePickerDialog.OnDateSetListener() {

                            @Override
                            public void onDateSet(DatePicker view, int year,
                                                  int monthOfYear, int dayOfMonth) {

                                txtDate.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);

                            }
                        }, mYear, mMonth, mDay);

   c.add(Calendar.MONTH,1);
            long afterOneMonthsinMilli=c.getTimeInMillis();
            datePickerDialog.getDatePicker().setMaxDate( afterOneMonthsinMilli );
            datePickerDialog.show();

                datePickerDialog.show();
            }
            if (v == btnTimePicker) {

                // Get Current Time
                final Calendar c = Calendar.getInstance();
                mHour = c.get(Calendar.HOUR_OF_DAY);
                mMinute = c.get(Calendar.MINUTE);

                // Launch Time Picker Dialog
                TimePickerDialog timePickerDialog = new TimePickerDialog(this,
                        new TimePickerDialog.OnTimeSetListener() {

                            @Override
                            public void onTimeSet(TimePicker view, int hourOfDay,
                                                  int minute) {

                                txtTime.setText(hourOfDay + ":" + minute);
                            }
                        }, mHour, mMinute, false);
                timePickerDialog.show();
            }
        }
    }