title: pandas tz_convert: difference among EST, US/Eastern and America/New_York
body: <p>It is my understanding that EST, US/Eastern and America/New_York should be the same, but apparently I was wrong. </p>
  
  <p>when I do the following: </p>
  
  <pre><code>pd.Timestamp('2011-07-03T07:00:00-04:00').tz_convert('US/Eastern')
  </code></pre>
  
  <p>which gave:</p>
  
  <pre><code>Timestamp('2011-07-03 07:00:00-0400', tz='US/Eastern')
  </code></pre>
  
  <p>when I do:</p>
  
  <pre><code>pd.Timestamp('2011-07-03T07:00:00-04:00').tz_convert('EST')
  </code></pre>
  
  <p>it gives:</p>
  
  <pre><code>Timestamp('2011-07-03 06:00:00-0500', tz='EST')
  </code></pre>
  
  <p>when I do:</p>
  
  <pre><code>pd.Timestamp('2011-07-03T07:00:00-40:00').tz_convert('America/New_York')
  </code></pre>
  
  <p>it gives:</p>
  
  <pre><code>Timestamp('2011-07-04 19:00:00-0400', tz='America/New_York')
  </code></pre>
  
  <p>could anyone give me some insight about this? I need to convert my timestamp so that it will be comparable with time for NYSE. Now I don't know which timezone to use. Thank you for your help.</p>
  
  <p>There is a typo in my code (thanks, BrenBarn), so timezone: America/New_York and US/Eastern are actually the same.</p>