How to reset chronometer in android ???

1. Use setBase() method to set the base to the  current time just before calling start(). Depending on your exact  needs you may need to add some logic around whether to reset the chronometer or not before starting it.
2. Here is the sample code
View.OnClickListener mStartButtonListener = new OnClickListener() {
        @Override
        public void onClick(View arg0) {
            mChronometer.setBase(SystemClock.elapsedRealtime());
            mChronometer.start();
        }
    };