Usage:

new CountUpTimer(1000L) {
    @Override
    public void onTick(long millisElapsed) {
        Date date = new Date(millisElapsed);
        DateFormat dateFormat = new SimpleDateFormat(TimeUnit.MILLISECONDS.toHours(millisElapsed) >= 1 ? "HH:mm:ss" : "mm:ss");
        Log.i(dateFormat.format(date));
    }
};