php script to count the no of days to a date in the future

The below given php script count and display the no of days to a specific date in the future...
< ? php
         $d=date("d");
         $m=date("m");
         $y=date("Y");
 // Change this to the day in the future    
 $dd = 13;
 // Change this to the month in the future
 $mm = 05;
 // Change this to the year in the future
 $yy =2011;

/*COUNT THE NO OF DAYS TO THE DATE IN THE FUTURE */

 $dy=$yy - $y;
 if ($dy ==0)
   { $dm = $mm - $m;
     $days=(($dm-1)*30)+(30-$d)+$dd+($dm/2);
     echo "\r\n There are $days days remaining \r\n";
   }
 else
   {
     $days=(($dy-1)*365)+(30-$d)+((12-$m)*30)+(($mm-1)*30)+$dd+($dy*4);
     echo " There are $days days remaining ";
   }
?>