Datepicker and Timepicker Dialog box

step 1:

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

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

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        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);

            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();
        }
    }

//https://www.codeproject.com/Articles/1112812/Android-Alert-Dialog-Tutorial-Working-with-Time-Pi

step 2:

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent"    
android:layout_height="match_parent"    
tools:context=".MainActivity">

    <EditText        
android:layout_width="200dp"        
android:layout_height="wrap_content"        
android:id="@+id/in_date"        
android:layout_marginTop="82dp"        
android:layout_alignParentTop="true"        
android:layout_alignParentLeft="true"        
android:layout_alignParentStart="true" />

    <Button        
android:layout_width="wrap_content"        
android:layout_height="wrap_content"        
android:text="SELECT DATE"        
android:id="@+id/btn_date"        
android:layout_alignBottom="@+id/in_date"        
android:layout_toRightOf="@+id/in_date"        
android:layout_toEndOf="@+id/in_date" />

    <EditText        
android:layout_width="200dp"        
android:layout_height="wrap_content"        
android:id="@+id/in_time"        
android:layout_below="@+id/in_date"        
android:layout_alignParentLeft="true"        
android:layout_alignParentStart="true" />

    <Button        
android:layout_width="wrap_content"        
android:layout_height="wrap_content"        
android:text="SELECT TIME"        
android:id="@+id/btn_time"        
android:layout_below="@+id/btn_date"        
android:layout_alignLeft="@+id/btn_date"        
android:layout_alignStart="@+id/btn_date" />
    </RelativeLayout>