title: LocalDate: parse MM-yyyy
body: <p>I get <code>java.time.format.DateTimeParseException</code> after attempt to do following:</p>
  
  <pre><code>LocalDate.parse( "09-2017" , DateTimeFormatter.ofPattern("MM-yyyy") )
  </code></pre>
  
  <p>What is wrong? Is there any utility in Java to check dateString formats? </p>