title: Validate a non existing date with moment js
body: <p>Good day to everyone.</p>
  
  <p>I need to validate a non-existing date with moment taking the value from a datepicker, so far I couldn't do it. For example:</p>
  
  <pre><code>moment('29/02/2021').isValid()
  </code></pre>
  
  <p>will return <code>true</code> as the format is correct but the <code>date</code> as is does not exist... The point with this is to show to the user an error message whenever the value passed to the datepicker is an invalid <code>date</code> or whatever else that is not a <code>date</code> (<code>123456789</code> or <code>asd</code> for example)</p>
  
  <p>Thank you for your help in advance</p>