How does what differ, Mike?  
<http://www.physci.org/codes/javafaq.jsp#netiquette>

Check for yourself.
<sscce>
// To gain smooth time based animation, the renderer needs
// to calculate the positions of the visible elements at the
// time of painting the Graphics object.
import java.awt.event.*;
import javax.swing.Timer;
import java.util.Date;

/** This example demonstrates the time drift of both a
Thread and a javax.swing.Timer set for '1 second' delay.
Using Java 1.5.0 beta, the Timer drifts off time faster
than the Thread.
@author Andrew Thompson */
public class TimeDrifter implements Runnable, ActionListener {

  /** The Timer used in this example */
  Timer timer;

  /** Time started. */
  long timerStart, threadStart;

  /** Duration of test in seconds (give or take 1). */
  final int DURATION = 120;

  /** Compile true for more detailed output
  but less acccurate results. */
  final boolean TEST = false;

  TimeDrifter() {
     //timer.addActionListener(this);
     Thread t = new Thread(this);

     System.out.println("Test duration: " + DURATION + " seconds." );
     System.out.println("Start thread test" );
     threadStart = System.currentTimeMillis();
     t.start();
  }

  public void timerStart() {
     timer = new Timer(1000, this);

     System.out.println("Start timer test" );
     timerStart = System.currentTimeMillis();
     timer.start();
  }

  /** Starts a new Thread to sleep for 1000 ms. */
  public void run() {
     while (true) {
        try {
           float timeInSec =
              (System.currentTimeMillis()-threadStart)/1000f;
           if (TEST) System.out.println("thread: \t" +
              (timeInSec-(int)timeInSec) );
           if ( (int)timeInSec>DURATION ) {
              System.out.println("thread drift:\t " +
                 (timeInSec-(int)timeInSec) +
                 " / over: " + (int)timeInSec + " seconds" );

              timerStart();

              Thread.sleep(DURATION*2*1000);
           } else {
              Thread.sleep(1000);
           }
        } catch (InterruptedException ie) {
              // ignore
        }
     }
  }

  public void actionPerformed(ActionEvent ae) {
     float timeInSec =
        (System.currentTimeMillis()-timerStart)/1000f;
     if (TEST) System.out.println("timer: \t" +
        (timeInSec-(int)timeInSec) );
     if ( (int)timeInSec>DURATION ) {
        timer.stop();
        System.out.println("timer drift: \t " +
           (timeInSec-(int)timeInSec) +
           " / over: " + (int)timeInSec + "seconds" );
        //((Runnable)this).Thread.interrupt();
        System.exit(0);
     }
  }

  public static void main(String[] args) {
     new TimeDrifter();
  }
}
</sscce>

Run 1;

Test duration: 120 seconds.
Start thread test
thread drift:    0.04399872 / over: 121 seconds
Start timer test
timer drift:     0.4850006 / over: 121seconds
<http://www.physci.org/test/graph/index.jsp?nm=Drift+in+ms&lbl=Thread+Timer&val=4
4+485&width=80>

Run 2:

Test duration: 120 seconds.
Start thread test
thread drift:    0.125 / over: 121 seconds
Start timer test
timer drift:     0.22399902 / over: 121seconds
<http://www.physci.org/test/graph/index.jsp?nm=Drift+in+ms&lbl=Thread+Timer&val=1
25+223&width=80>

Run 3:

Test duration: 120 seconds.
Start thread test
thread drift:    0.033996582 / over: 121 seconds
Start timer test
timer drift:     0.20400238 / over: 121seconds
<http://www.physci.org/test/graph/index.jsp?nm=Drift+in+ms&lbl=Thread+Timer&val=3
4+204&width=80>

Run 4:
Test duration: 120 seconds.
Start thread test
thread drift:    0.024002075 / over: 121 seconds
Start timer test
timer drift:     0.2539978 / over: 121seconds
<http://www.physci.org/test/graph/index.jsp?nm=Drift+in+ms&lbl=Thread+Timer&val=2
4+254&width=80>

HTH