Android : MediaPlayer Duration currentTime and endTime

Android MediaPlayer duration currentTime and endTime, still showing, like this:

 currentTime - 0m:4s    
 endTime - 4m: 9s

but want to show like this:

 currentTime - 00m:04s
 endTime - 04m:09s

code looks like this:

      endTimeField.setText(String.format("%dm:%ds", 
         TimeUnit.MILLISECONDS.toMinutes((long) finalTime),
         TimeUnit.MILLISECONDS.toSeconds((long) finalTime) - 
         TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
         toMinutes((long) finalTime)))
      );
      startTimeField.setText(String.format("%dm:%ds", 
         TimeUnit.MILLISECONDS.toMinutes((long) startTime),
         TimeUnit.MILLISECONDS.toSeconds((long) startTime) - 
         TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
         toMinutes((long) startTime)))
      );   

 ......................

  private Runnable UpdateSongTime = new Runnable() {
      public void run() {
         startTime = mediaPlayer.getCurrentPosition();

         startTimeField.setText(String.format("%dm:%ds", 
            TimeUnit.MILLISECONDS.toMinutes((long) startTime),
            TimeUnit.MILLISECONDS.toSeconds((long) startTime) - 
            TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
            toMinutes((long) startTime)))
         );
         seekbar.setProgress((int)startTime);
         myHandler.postDelayed(this, 100);
      }
   };