title: How to get system timezone setting and pass it to pytz.timezone?
body: <p>We can use <code>time.tzname</code> get a local timezone name, but that name is not compatible with <code>pytz.timezone</code>.</p>
  
  <p>In fact, the name returned by <code>time.tzname</code> is ambiguous. This method returns <code>('CST', 'CST')</code> in my system, but 'CST' can indicate four timezones:</p>
  
  <ul>
  <li>Central Time Zone (North America) - observed in North America's Central Time Zone</li>
  <li>China Standard Time</li>
  <li>Chungyuan Standard Time - the term "Chungyuan Standard Time" is now rarely in use in Taiwan</li>
  <li>Australian Central Standard Time (ACST)</li>
  </ul>