日付選択ダイアログ

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

final DatePickerDialog datePickerDialog = new DatePickerDialog(
  this,
  new DatePickerDialog.OnDateSetListener() {
    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
      Log.v("", String.valueOf(year) + "/" +
      String.valueOf(monthOfYear + 1) + "/" + 
      String.valueOf(dayOfMonth));
    }
  }, year, month, day);
  datePickerDialog.show();
}

時刻選択ダイアログ

final Calendar calendar = Calendar.getInstance();
final int hour = calendar.get(Calendar.HOUR_OF_DAY);
final int minute = calendar.get(Calendar.MINUTE);
final TimePickerDialog timePickerDialog = new TimePickerDialog(this,
  new TimePickerDialog.OnTimeSetListener() {
    @Override
    public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
      Log.v("", String.valueOf(hourOfDay) + ":" + String.valueOf(minute));
    }
  }, hour, minute, true);
  timePickerDialog.show();
}