Php to automatically increase date after date has been reached?

Was bored so I wrote this:

<?php
// get the expiry date from the text file
$handle = fopen('expiry.txt', 'r') or die("can't open file");
$expiry_date = fread($handle, filesize('expiry.txt'));
fclose($handle);

$now = date('d-m-Y');

// check to see if the current date matches or is over
if (check_date($now, $expiry_date)) {
// TRUE so update the text file and show new expiry

// generate the new date
$newdate = date('d-m-Y', strtotime('+7 days'));

// save to file
$handle = fopen('expiry.txt', 'w') or die("can't open file");
fwrite($handle, $newdate);
fclose($handle);

// show new date
print $newdate;
}
else {
// FALSE so show expiry date
print $expiry_date;
}

// function to check if current date is greater than expiry
function check_date($start_date, $end_date) {
$start = strtotime($start_date);
$end = strtotime($end_date);
if ($start - $end > 0) {
return 1;
}
else {
return 0;
}
}
?>


Just put the code in a new PHP file and create a new text file called expiry.txt. In the expiry.txt file put the expiry date in like this: 14-06-2011 and then save the file. Upload both files so that they are in the same directory on the server.