JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.7.0/moment.min.js"></script>
<div id='output'></div>

JavaScript

function calculate(endTime) {
    var timeStops = [];
    var startTime = moment().add('m', 15 - moment().minute() % 15);

    while (startTime < endTime) {
        timeStops.push(new moment(startTime));
        startTime.add('m', 15);
    }

    return timeStops;
}

var result = calculate(moment().add('h', 1));
var output = document.getElementById('output');

output.innerHTML = '<ul><li>' + result.join('</li><li>') + '</li></ul>';