JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/css/bootstrap.min.css">
<link rel="stylesheet" href="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/css/datepicker3.css">
<script src="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/js/bootstrap-datepicker.js"></script>
<div class="datepicker" id="datepicker1"></div>

JavaScript

$(function () {

    $('.datepicker').datepicker({
        format: 'yyyy-mm-dd',
        multidate: true,
        multidateSeparator: ",",
        calendarWeeks: true,
        todayHighlight: true
    }).on('changeDate', function (e) {
        var selecteddates = $('.datepicker').datepicker('getDates');
        var formatedSelectedDates = [];
        for (var date in selecteddates) {
            formatedSelectedDates.push(convertDate(selecteddates[date]));
        }
        alert(formatedSelectedDates);
    });

});

function convertDate(d) {
    function pad(s) {
        return (s < 10) ? '0' + s : s;
    }

    return [d.getFullYear(), pad(d.getMonth() + 1), pad(d.getDate())].join('-');
}