Refreshing a page without opending an index.php on the server POSSIBLE????

Refreshing a page without opending an index.php on the server POSSIBLE????

[Condition]
1. Upload this index file to the host server.

2. Nobody will force the index.php to open and 
 the index.php will never open or be loaded.


[Question]
Under the above condition, is the header going to work?
Namely, the message will be sent.


=======================================

<!Doctype>
<html>
<head>
</head>
<script>
 //Ajax Code will be here.
 // codes necessary to send message...
</script>
<body>

<?php
header("Refresh:3600");
echo date('Y:m:d H:i:s");
$message = 'Hi';

function sendMessage($message){
 //code
 //code
 $target = "012-334-3434";
 // send $message to $target.
}

sendMessage($message);

?>

</body>
</html>