There is a bug in Android's TimePicker for 4.0+. The onTimeChanged() callback in the onTimeChangedListener() is not called when the user changes am/pm. This sample code shows a workaround for the Android TimePicker in 4.0+, demonstrating a TextView that is always in sync with the TimePicker, regardless of which vertical spinner is being manipula…

ActivityMain.java

// This is for API 15-17+
// Tested on 4.0.3
public class ActivityMain extends Activity {
    ImageButton buttonTimeDone;
    NumberPicker numberPickerAmPm;
    TextView textViewTime;
    TimePicker timePickerMain;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setupViews();
        setupTimePickerListener();
    }
	
    private void setupViews() {
        buttonTimeDone = (ImageButton) findViewById(R.id.buttonTimeDone);
        textViewTime = (TextView) findViewById(R.id.textViewTime);
        timePickerMain = (TimePicker) findViewById(R.id.timePickerMain);
    }
	
    private void setupTimePickerListener() {
        timePickerMain.setIs24HourView(DateFormat.is24HourFormat(this));
		
        timePickerMain.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
        public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
            if (DateFormat.is24HourFormat(ActivityMain.this)) {
                textViewTime.setText("At: " + hourOfDay + ":" + minute);
            } else {
                if (hourOfDay == 0) { hourOfDay = 12; }
                    textViewTime.setText("At: " + ((hourOfDay > 12)?hourOfDay-12:hourOfDay) + ":" + ((minute < 10)?"0":"") + minute + ((numberPickerAmPm.getValue() == 0)?" am":" pm"));
                }
            }
        });
		
        numberPickerAmPm  = (NumberPicker)((ViewGroup) timePickerMain.getChildAt(0)).getChildAt(3);
        numberPickerAmPm.setOnValueChangedListener(new OnValueChangeListener() { 
            @Override
            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
                int hourOfDay = (timePickerMain.getCurrentHour() + 12) % 24;
                int minute = timePickerMain.getCurrentMinute();
                timePickerMain.setCurrentHour(hourOfDay);
                if (hourOfDay == 0) { hourOfDay = 12; }
                if (picker.getValue() == 0) {
                    textViewTime.setText("At: " + ((hourOfDay > 12)?hourOfDay-12:hourOfDay) + ":" + ((minute < 10)?"0":"") + minute + " am");
                } else {
                    textViewTime.setText("At: " + ((hourOfDay > 12)?hourOfDay-12:hourOfDay) + ":" + ((minute < 10)?"0":"") + minute + " pm");
                } 
            }
        });
    }
}

this is not working with me on Android 6