How to validate the date for dd/mm/yyyy with javascript. Simply match pattern

<input type="text" id="dob" value="01/01/1997">
<script>
var input = document.getElementById('dob').value;
var pattern =/^([0-9]{2})/([0-9]{2})/([0-9]{4})$/;
var result= pattern.test(input);
if(result){
  alert('Done');

// your condition
}else{
    alert('Wrong Format');

// your condition
}
</script>