Getting yesterdays date with time zone
<p>Hi I was able to find the answer to this question but now with the timezone included (http://stackoverflow.com/questions/1712116/formatting-yesterdays-date-in-python)</p>

<p>This is working fine for me:</p>

<pre><code>&gt;&gt;&gt; import time
&gt;&gt;&gt; time.strftime('/%Z/%Y/%m/%d')
'/EST/2013/01/18'
</code></pre>

<p>but is there a way to get the yesterdays date? 
I need to handle the timezone change when we switch from EST to EDT, EDT to EST</p>

<p>datetime modules allows to use timedelta, but the naive object don't support timezones by default and I'm not sure how to handle that.</p>
