title: Printing datetime as pytz.timezone("Etc/GMT-5") yields incorrect result
body: <p>Consider the following example, where I take a naive datetime, make it timezone aware in UTC, and then convert to UTC-5:</p>
  
  <pre><code>d1 = datetime.datetime(2019,3,7, 7,45)
  
  d2 = pytz.utc.localize(d1)
  print(f'UTC  : {d2}')
  
  d3 = d2.astimezone(pytz.timezone('Etc/GMT-5'))
  print(f'UTC-5: {d3}')
  </code></pre>
  
  <p>The output of this is:</p>
  
  <blockquote>
  <pre><code>UTC  : 2019-03-07 07:45:00+00:00
  UTC-5: 2019-03-07 12:45:00+05:00
  </code></pre>
  </blockquote>
  
  <p>I would have expected the <code>UTC-5</code> time to be <code>02:45</code>, but the 5 hour offset is being <strong>added</strong> to UTC, rather than subtracted.</p>
  
  <p><strong>Questions:</strong></p>
  
  <ul>
  <li>Why is the <code>'Etc/GMT-5'</code> offset applied to UTC +5 hours instead of -5 hours?</li>
  <li>How can I convert from <code>UTC</code> to <code>UTC-5</code>?</li>
  </ul>