Tryit Editor v2.7

Edit This Code:
<!DOCTYPE html>
<html>
<body>

<form action="form_action.asp">
  Date: <input type="datetime" id="myDatetime" name="date">
  <input type="submit">
</form>

<p>Click the "Try it" button to set the required property for the datetime field.</p>

<p><strong>Tip:</strong> Click the "Submit" button before and after you have clicked the "Try it" button, to see the effect.</p>

<button onclick="myFunction()">Try it</button>

<p><strong>Note:</strong> input elements with type="datetime" are not supported in any of the major browsers, except partially in Safari.</p>

<p id="demo"></p>

<script>
function myFunction() {
    document.getElementById("myDatetime").required = true;
    document.getElementById("demo").innerHTML = "The required property was set. The datetime field must now be filled out before submitting the form.";
}
</script>

</body>
</html>