Time difference between two times

finally did it yuppiiieee ...

package com.timedynamicllyupdate;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity 
{
    TextView current;
    private TextView txtCurrentTime;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Thread myThread = null;
        Runnable myRunnableThread = new CountDownRunner();
        myThread= new Thread(myRunnableThread);   
        myThread.start();

        current= (TextView)findViewById(R.id.current);
    }


    public void doWork() 
    {
        runOnUiThread(new Runnable() 
        {
            public void run() 
            {
                try
                {
                    SimpleDateFormat sdf = new SimpleDateFormat("hh:mm:ss aa");

                    txtCurrentTime= (TextView)findViewById(R.id.mytext);

                    Date systemDate = Calendar.getInstance().getTime();
                    String myDate = sdf.format(systemDate);
//                  txtCurrentTime.setText(myDate);

                    Date Date1 = sdf.parse(myDate);
                    Date Date2 = sdf.parse("02:50:00 pm");

                    long millse = Date1.getTime() - Date2.getTime();
                    long mills = Math.abs(millse);

                    int Hours = (int) (mills/(1000 * 60 * 60));
                    int Mins = (int) (mills/(1000*60)) % 60;
                    long Secs = (int) (mills / 1000) % 60;

                    String diff = Hours + ":" + Mins + ":" + Secs; // updated value every1 second
                    current.setText(diff);
                }
                catch (Exception e) 
                {

                }
            }
        });
    }

    class CountDownRunner implements Runnable
    {
        // @Override
        public void run() 
        {
            while(!Thread.currentThread().isInterrupted())
            {
                try 
                {
                    doWork();
                    Thread.sleep(1000); // Pause of 1 Second
                } 
                catch (InterruptedException e) 
                {
                        Thread.currentThread().interrupt();
                }
                catch(Exception e)
                {
                }
            }
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) 
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

To Calculate the difference between two dates you could try something like:

long millis = date1.getTime() - date2.getTime();
int hours = (int) (millis / (1000 * 60 * 60));
int mins = (int) ((millis / (1000 * 60)) % 60);

String diff = hours + ":" + mins; 

To update the Time Difference every second you can make use of Timer.

Timer updateTimer = new Timer();
updateTimer.schedule(new TimerTask() {
    public void run() {
        try {
            long mills = date1.getTime() - date2.getTime();
                int hours = millis/(1000 * 60 * 60);
                 int mins = (mills/(1000*60)) % 60;

                 String diff = hours + ":" + mins; // updated value every1 second
            } catch (Exception e) {
            e.printStackTrace();
        }
    }

}, 0, 1000); // here 1000 means 1000 mills i.e. 1 second

Edit : Working Code :

public class MainActivity extends Activity {

    private TextView txtCurrentTime;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        txtCurrentTime= (TextView)findViewById(R.id.mytext);
        Timer updateTimer = new Timer();
        updateTimer.schedule(new TimerTask() 
        {
            public void run() 
            {
                try 
                {
                    
                    SimpleDateFormat format = new SimpleDateFormat("hh:mm:ss aa");
                    Date date1 = format.parse("08:00:12 pm");
                    Date date2 = format.parse("05:30:12 pm");
                    long mills = date1.getTime() - date2.getTime();
                    Log.v("Data1", ""+date1.getTime());
                    Log.v("Data2", ""+date2.getTime());
                    int hours = (int) (mills/(1000 * 60 * 60));
                    int mins = (int) (mills/(1000*60)) % 60;

                    String diff = hours + ":" + mins; // updated value every1 second
                    txtCurrentTime.setText(diff);
                } 
                catch (Exception e) 
                {
                    e.printStackTrace();
                }
            }

        }, 0, 1000);
    }