how to get the following link to work in phpmailer - html

Question

I have the following phpmailer and have displayed the date by using php echo but the problem is that, if the user were to delete the date, then the date won't work. What is the best way to prevent an user from deleting information displayed in the placeholder?
<?php
ob_start();
include_once __DIR__.'/header2.php';
if(!isset($_SESSION['u_uid'])) {
echo "<meta http-equiv='refresh' content='0;url=index.php?subscribed=notlogin'>";
exit();
} else {
if($_SESSION['u_permission'] == 0) {
echo "<meta http-equiv='refresh' content='0;url=header2.php?subscribed=nopermission'>";
exit();
} else {
$date = strip_tags(date('Y-m-d H:i:s'));
echo '<form action="subscribed_form.php" method="POST"><table class="subscribed">
<tr>
<th colspan="3" class="update_title">Welcome to the Administrator\'s Display Subscribed Newsletter Members\s Section</th>
</tr>';
echo '
<tr>
<th>Newsletter\'s name:</th><td><input type="text" name="name" value="Enter Newsletter\'s Name"></td>
</tr>
<tr>
<th>Newsletter\'s Description:</th><td><textarea name="description" value="Enter Newsletter\'s Description"></textarea></td>
</tr>
<tr>
<th>Newsletter\'s Date:</th><td><input type="text" name="date" value="'.htmlspecialchars($date).'"></td>
</tr>
<tr><th></th><td><input type="submit" name="submit" value="Send Newsletters"></td></tr></table></form>';
}
}