title: How to validate a ISO Format (YYYY-MM-DD) date validation in libreoffice or VBA. If its other than YYYY-MM-DD it should give me an error message
body: <p>Have to check the date format validation in my code</p>
  
  <p>If it's <code>YYYY-MM-DD</code> it is okay to proceed, otherwise exit the loop</p>
  
  <p>something like this</p>
  
  <pre><code>if date is not in YYYY-MM-DD format  
    Msgbox "please enter a valid format of YYYY-MM-DD  
  exit     
  else  
     all those calcualtions  
  end if
  </code></pre>