Android : How to Stop The Text View Updates when button is clicked?

I am new to Android. I have four states like: driving, onDuty, offDuty and sleep. When I click on the driving button Automatically Time Updates in the Textview. It's working fine for me. Here is my code:

 btnDriving.setonClickListener(new View.onClickListener)
{
 private void UpdatingDrvingCircle() {
        new Thread() {
            @Override
            public void run() {
                try {
                    while (!isInterrupted()) {
                        Thread.sleep(1000);

                        if(getActivity() == null)
                            return;
                        getActivity().runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                updateDrivingTextView();
                            }
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }
}

 private void updateDutyTextView(){

    final DateTime dt=DateTime.now() ;
        String pattern = " KK:mm:ss";
        DateTimeFormatter fmt;
     fmt=DateTimeFormat.forPattern(pattern);
            DateTime et=DateTime.now();
            fmt=DateTimeFormat.forPattern(pattern);
            String sTime=dt.toString(fmt);
            String eTime=et.toString(fmt);

            DateTime d1 = fmt.parseDateTime(sTime);
            DateTime  d2 = fmt.parseDateTime(eTime);

            DateTime dt1 = new DateTime(d1);
            DateTime dt2 = new DateTime(d2);
            int hours=Hours.hoursBetween(dt1, dt2).getHours() % 24;
            int minutes=Minutes.minutesBetween(dt1, dt2).getMinutes() % 60;
            int LeftHours=AppConstants.DRIVING_11_HOUR-hours;
            int LeftMins=AppConstants.DRIVING_MINUTE-minutes;
            tvDutyTimeLeft.setText(LeftHours+" hr "+LeftMins+" m left");

}

Here I have one More Button i.e..btnOnDuty. When I click on that Button the Previous Button Text View Updates are stopped. Could anyone help me figure out why?

Here is btnDuty Code

btnOnDuty.setonClickListener()
{
UpdatingDutyCircle();
}
 private void UpdatingDutyCircle() {
        Thread t=new Thread() {
            @Override
            public void run() {
                try {
                    while (!isInterrupted()) {
                        Thread.sleep(1000);
                        getActivity().runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                updateDutyTextView();
                            }
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }


            }
        };t.start();
    }

 private void updateDutyTextView() {

        fmt=DateTimeFormat.forPattern(pattern);
        DateTime et=DateTime.now();
        fmt=DateTimeFormat.forPattern(pattern);
        String sTime=dt.toString(fmt);
        String eTime=et.toString(fmt);

        DateTime d1 = fmt.parseDateTime(sTime);
        DateTime  d2 = fmt.parseDateTime(eTime);

        DateTime dt1 = new DateTime(d1);
        DateTime dt2 = new DateTime(d2);
        int hours=Hours.hoursBetween(dt1, dt2).getHours() % 24;
        int minutes=Minutes.minutesBetween(dt1, dt2).getMinutes() % 60;
        int LeftHours=AppConstants.DRIVING_14_HOUR-hours;
        int LeftMins=AppConstants.DRIVING_MINUTE-minutes;

        int TotalHrs=hours*60+minutes;
        btnOnDuty.setText(""+hours+"hr "+ minutes +"m");
        pbOnDuty.setMax(660);
        pbOnDuty.setProgress(TotalHrs);
        tvDutyTimeLeft.setText(LeftHours+" hr "+LeftMins+" m left");
    }