​x
 
<!DOCTYPE html>
<html>
<body>
​
<h2>JavaScript Date Object</h2>
<p>This "home made" isDate() function returns true when used on an date:</p>
​
<p id="demo"></p>
​
<script>
const myDate = new Date();
document.getElementById("demo").innerHTML = isDate(myDate);
​
function isDate(myDate) {
  return myDate.constructor === Date;
}
</script>
​
</body>
</html>
​