title: OpenSSL: explicitly set start/end date using `openssl req`?
body: <p>Using the <code>openssl req</code> tool, is it possible to explicitly specify the start and end dates on the certificate (eg, like the <code>-startdate</code> and <code>-enddate</code> options to <code>openssl ca</code>)?</p>
  
  <p>I would like to create a certificate which is valid between a date in the past and a date in the future.</p>