Moment.js Sandbox
by Arvind Pal
HTML
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>
JavaScript
//var now = moment().format('MMM DD h:mm A');
function getLastDayOfQuarterMonth(date) {
let retVal = moment().quarter(3).endOf('quarter').format('MM-DD-YYYY');
return retVal
}
let date = "05-04-2020";
alert(getLastDayOfQuarterMonth(date));