ValidDate
HTML
<html>
<body>
<span id="input">33.133.2020</span>
</body>
</html>JavaScript
var dateformat = /^(0?[1-9]|[12][0-9]|3[01])\.(0?[1-9]|1[012])\.\d{4}$/;
var strdate=input.innerText;
var date=new Date(strdate.split(".")[2],strdate.split(".")[1],strdate.split(".")[0]);
alert(isValidDate(date))
function isValidDate(dateObject){
return new Date(dateObject).toString() !== 'Invalid Date';
}