Can I test for daylight saving time (DST) using PHP date()?
<p>I'm looking at PHP <code>date()</code> documentation and thought that <code>'I'</code> would tell me whether the date supplied was in DST. So I expected the following:</p>

<pre><code>$d = strtotime('2012-07-01 12:30:00, Europe/London'); // this is in DST
$bool = date('I',$d); // 1
</code></pre>

<p>but got this:</p>

<pre><code>$bool = date('I',$d); // 0
</code></pre>

<p>Obviously I'm reading the documentation wrong. I know I can do this using <code>dateTimeZone()</code> transitions, but is this not a feature of <code>date()</code> as well?</p>
