Converting date (with milliseconds) into timestamp
<p>I have date format like <code>'25 May 2016 10:45:53:567'.</code></p>

<p>I want to convert into the time stamp.</p>

<p><code>strtotime</code> function returns empty.</p>

<pre><code>$date = '25 May 2016 10:45:53:567';
echo strtotime($date); 
// returns empty
</code></pre>

<p>When I removed the milliseconds, it's working.</p>

<pre><code>$date = '25 May 2016 10:45:53';
echo strtotime($date);
// returns 1464153353
</code></pre>

<p>Please sort out my issue. Thanks in advance.</p>