PHP: how to subtract e.g 9 days from filectime()
<p>I want to delete all files older than 9 days. Since filectime returns the creation time of a </p>

<p>certain file, therefore, I just want to know how to subtract for an example: 9 days from the </p>

<p>filectime().</p>

<p><strong>Code</strong>:</p>

<pre><code>'&lt;?php
 $filename = 'JSONFormate.json';
 if (file_exists($filename)) {
echo "$filename was last changed: " . date("F D Y H:i:s.", filectime
($filename));
echo "\n......".filectime($filename)-777600;
}'
?&gt;
</code></pre>

<p><strong>Result</strong>
JSONFormate.json was last changed: May Tue 2012 22:50:10.-777600</p>
