Moment.js Sandbox
HTML
<script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.2.1/moment.min.js"></script>
JavaScript
var now = moment().format('MMM DD h:mm A');
var destinationTime = moment("2019-05-07T16:59:00");
let temp = moment.utc(moment(destinationTime, "yyyy-MM-dd'T'hh:mm:ss").diff(moment(new Date(), "yyyy-MM-dd'T'hh:mm:ss"))).format("HH:mm:ss")
alert(temp);