ValueSection
by Checha Man
HTML
<!-- Learn about this code on MDN: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/datetime-local -->
<label for="party">Enter a date and time for your party booking:</label>
<input id="party" type="datetime-local" name="partydate" value="2017-06-01T08:30">
JavaScript
var dateControl = document.querySelector('input[type="datetime-local"]');
dateControl.value = '2017-06-01T08:30';