title: Converting date string to time in millis returns negative number
body: <p>I'm trying to convert a string date with the following pattern 20221231 into a Long (to get the time in millis).
  I've tried many ways to do it but I always get a negative number.</p>
  <p>My last solution is using DateUtils from apache as follow:
  <code>return DateUtils.parseDate(dateString, DATE_FORMAT).getTime();</code></p>
  <p>with <code>DATE_FORMAT</code> equals <code>yyyyMMdd</code>
  I've also tried format <code>YYYYMMDD</code>
  but for some reason I always get a negative number</p>
  <p>EX: for a string date 19330601, I get -1154566800000</p>
  <p>Any idea ? thanks</p>