Fatal error: Call to undefined function easter_date()
<p>I'm trying to get the easter_date from this year.
This is my code:</p>

<pre><code>&lt;?php
$year = date ("Y");
$easter = date ("d-M-Y", easter_date ($year));
echo "Easter " . $year . ": " . $easter . "";
?&gt;</code></pre>

<p>When I execute the code following error appears:
Fatal error: Call to undefined function easter_date() in</p>

<p>My phpVersion is 5.3.3. I'm using Linux(Ubuntu).</p>

<p>Have you got an idea what is missing?</p>
