Question

I am trying to make a stopwatch in android that includes hours and milliseconds. My chronometer always starts at 7:00:00.000 or in 24 hour format 19:00:00.000. Here is the code:

public class MainActivity extends Activity {
   TextView tv;
   long init,now,time;

   @Override
   public void onCreate(Bundle savedInstanceState) {
       //...
       myChronometer.setOnChronometerTickListener(new OnChronometerTickListener() {
            public void onChronometerTick(Chronometer cArg) {
                SimpleDateFormat timeFormat = new SimpleDateFormat("hh:mm:ss.S");
                now=System.currentTimeMillis();
                time=now-init;
                String s2 = timeFormat.format(time);
                tv.setText(s2);
            }
        });
       final ImageButton buttonStart = (ImageButton)findViewById(R.id.start);
       buttonStart.setOnClickListener(new Button.OnClickListener(){
       @Override
       public void onClick(View v) {
           init=System.currentTimeMillis();
           myChronometer.setBase(init);
           myChronometer.start();
       }});

   }

}

Is there anyway to start the chronometer at zero and continue the time from there?
Thank you

Answer 1

The 7 hour difference is likely due to your timezone. SimpleDateFormat uses your system’s timezone by default, whereas System.currentTimeMillis() gives you the time in UTC.

This should fix your problem, in onChronometerTick():

SimpleDateFormat timeFormat = new SimpleDateFormat("H:mm:ss.S");
timeFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
now=System.currentTimeMillis();

Notice I changed hh to H in your format string.