Toast displayed twice

I have two spinners in a fragment, one of the spinner will display toast message when an item is selected. The problem is the toast in the first if-else statement displayed twice. Once when open the fragment and the second time when the item selected.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    mRootView = inflater.inflate(R.layout.add, container, false);



    //------------------------------unit Spinner adapter---------------------------------------//
    Spinner spinner = (Spinner) mRootView.findViewById(R.id.units);

    //Create ArrayAdapter using string array and default spinner
    ArrayAdapter<CharSequence> sAdapter = ArrayAdapter.createFromResource(getActivity(), R.array.units, android.R.layout.simple_spinner_dropdown_item);

    //Specify layout to use when list of choices appears
    sAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    //Apply adapter to the spinner
    spinner.setAdapter(sAdapter);


    //----------------------------reminder Spinner adapter-------------------------------------//
    Spinner reminderSpinner = (Spinner) mRootView.findViewById(R.id.list_reminder);
    ArrayAdapter<CharSequence> reminderAdapter = ArrayAdapter.createFromResource(getActivity(), R.array.countdown_reminder, android.R.layout.simple_spinner_dropdown_item);
    reminderAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    reminderSpinner.setAdapter(reminderAdapter);



    spinner.setOnItemSelectedListener(spinnerListener);
    reminderSpinner.setOnItemSelectedListener(spinnerListener);

return mRootView;
}


    //---------------------------------Spinner Listener----------------------------------------//
    AdapterView.OnItemSelectedListener spinnerListener = new AdapterView.OnItemSelectedListener() {

        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

            switch (parent.getId()) {

                case R.id.units:
                    String selectedUnit = parent.getItemAtPosition(position).toString();
                    break;
                case R.id.list_reminder:
                    String reminder = parent.getItemAtPosition(position).toString();


                    if (reminder.equals("24 hours")) {
                        Toast.makeText(getActivity(), "Reminder has been set 24 hours from the selected date", Toast.LENGTH_LONG).show();

                    } else if (reminder.equals("2 days")) {
                        Toast.makeText(getActivity(), "Reminder has been set 2 days from the selected date", Toast.LENGTH_LONG).show();

                    } else if (reminder.equals("3 days")) {
                        Toast.makeText(getActivity(), "Reminder has been set 3 days from the expiry date", Toast.LENGTH_LONG).show();

                    } else if (reminder.equals("1 week")) {
                        Toast.makeText(getActivity(), "Reminder has been set 1 week from the selected date", Toast.LENGTH_LONG).show();

                    } else if (reminder.equals("2 weeks")) {
                        Toast.makeText(getActivity(), "Reminder has been set 2 weeks from the selected date", Toast.LENGTH_LONG).show();

                    } else if (reminder.equals("1 month")) {
                        Toast.makeText(getActivity(), "Reminder has been set 1 month from the selected date", Toast.LENGTH_LONG).show();
                    }
                    break;
            }
        }


        public void onNothingSelected(AdapterView<?> parent) {
        }
    };
    //------------------------------------end spinner code-------------------------------------//

The '24 hours' toast displayed when user open the fragment and when the '24 hours' selected. I can't figure out what's wrong with the code. Help please?!