Tryit Editor v2.7

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

Date: <input type="datetime-local" id="myLocalDate" value="2014-11-16T15:00:33">

<p>Click the button to decrement the value of the datetime field by 10 minutes (each time you click).</p>

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

<p><strong>Note:</strong> The stepDown() method is not supported by Internet Explorer.</p>
<p><strong>Note:</strong> input elements with type="datetime-local" are not supported in Internet Explorer or Firefox.</p>

<script>
function myFunction() {
    document.getElementById("myLocalDate").stepDown(10);
}
</script>

</body>
</html>