Include footer not working Options

[HenryH]

New to all this so please be gentle with me !

Have created a simple .php file :

CODE

<?php
echo "<p>Copyright © 2016-" . date("Y") . " Some info?</p>";
?>

The intention being to create a uniform footer for each webpage.
On the HTML file for the webpage I have the line :-

CODE

<?php include 'footer.php';?>

(OR <?php include '/footer.php';?>)

I get NOTHING included on my webpage.
What an I doing that is wrong??

Any help much appreciated.