<!DOCTYPE html>
<html>
<body>
Birthday: <input type="date" id="myDate" value="2000-05-05">
<p>Click the button to change the default value of the date field.</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> input elements with type="date" do not show as any date field/calendar in Firefox.</p>
<script>
function myFunction() {
document.getElementById("myDate").defaultValue = "2014-02-09";
}
</script>
</body>
</html>