title: Why Python pytz package has both Asia/Kolkata and Asia/Calcutta timezones?
body: <p>I was working on a dropdown with list of all timezones and I took the list of timezones from Python <strong>pytz</strong> package. I noticed that Asia/Kolkata and Asia/Calcutta both appear in the list where as Asia/Calcutta has been renamed to Asia/Kolkata. Is there a reason pytz is not removing the obsolete timezones?</p>
  <p>Same with Asia/Katmandu and Asia/Kathmandu.</p>