Tryit Editor v2.7

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

Birthday: <input type="datetime" id="myDatetime">

<p>Click the button to set the datetime field to read-only.</p>

<p><strong>Tip:</strong> To see the effect, try to type something in the datetime field before and after clicking the button.</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").readOnly = true;
}
</script>

</body>
</html>