title: What does this to_date() function of PLSQL do?
body: <pre><code>TO_CHAR((  TO_DATE(calendar_key,'YYYYMMDD' )+ 1),'IW') week
  </code></pre>
  
  <p>Can somebody tell me what's happening in this query?
  I know what the to_date operation does, I am confused about the '+1' over there, does it add 1 year to the date?? </p>
  
  <p>And what about the 'IW'? Is it alias name? and then why 'week'?</p>
  
  <p>Plese help me. Thanks in advance</p>