title: Jackson accepting negative dates
body: <p>I am trying to get a date field from JSON in a spring-boot application with Jackson. The JSONFormat looks like this:</p>
  
  <pre><code>@NotNull(message = ValidationErrors.NOT_BLANK_MESSAGE)
  @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyyMMdd")
  private Date date;
  </code></pre>
  
  <p>It works fine for most of the cases but when I pass 2017-0526, it is automatically converting it to 10th of May, 2018.</p>
  
  <p>I want to throw exception in case the date is not in the yyyyMMdd format or contains minus sign. I tried going through stack overflow and Jackson documentation, but couldn't find anything.</p>
  
  <p>Why is JsonFormat accepting negative dates?</p>
  
  <p>Is there any workaround for this, so that it throws exception when such dates are passed?</p>