Revised example to support fragments, from http://androidexample.com/In_this_example_creating_a_date_picker_to_pick_day__month_year_of_date/index.php?view=article_discription&aid=89&aaid=113

gistfile1.txt

package com.jawnnypoo.example;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;


public class MainActivity extends Activity {
    private TextView Output;
    private Button changeDate;
    private DatePickerFragment mDatePickerFragment;

    private int year;
    private int month;
    private int day;

    private static final String TAG_DATE_PICKER = "DATE_PICKER";

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

        Output = (TextView) findViewById(R.id.Output);
        changeDate = (Button) findViewById(R.id.changeDate);

        // Get current date by calender

        final Calendar c = Calendar.getInstance();
        year  = c.get(Calendar.YEAR);
        month = c.get(Calendar.MONTH);
        day   = c.get(Calendar.DAY_OF_MONTH);

        mDatePickerFragment = new DatePickerFragment();
        mDatePickerFragment.setOnDateSetListener(pickerListener);

        // Show current date

        Output.setText(new StringBuilder()
                // Month is 0 based, just add 1
                .append(month + 1).append("-").append(day).append("-")
                .append(year).append(" "));

        // Button listener to show date picker dialog

        changeDate.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // On button click show datepicker dialog
                mDatePickerFragment.show(getFragmentManager(), TAG_DATE_PICKER);

            }

        });
    }

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

        // when dialog box is closed, below method will be called.
        @Override
        public void onDateSet(DatePicker view, int selectedYear,
                              int selectedMonth, int selectedDay) {

            year  = selectedYear;
            month = selectedMonth;
            day   = selectedDay;

            // Show selected date
            Output.setText(new StringBuilder().append(month + 1)
                    .append("-").append(day).append("-").append(year)
                    .append(" "));

        }
    };

    public static class DatePickerFragment extends DialogFragment
            implements DatePickerDialog.OnDateSetListener {

        private DatePickerDialog.OnDateSetListener mListener;

        @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);

            // Create a new instance of DatePickerDialog and return it
            return new DatePickerDialog(getActivity(), this, year, month, day);
        }

        public void onDateSet(DatePicker view, int year, int month, int day) {
            // Do something with the date chosen by the user
            if (mListener != null) {
                mListener.onDateSet(view, year, month, day);
            }
        }

        public void setOnDateSetListener(DatePickerDialog.OnDateSetListener onDateSetListener) {
            mListener = onDateSetListener;
        }
    }
}