JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.js"></script>
<script src="https://github.com/eternicode/bootstrap-datepicker/blob/master/js/bootstrap-datepicker.js"></script>
<div class="form-group" id="month-group-container">
    <label for="startDate">Month</label>
    <div class="input-group date">
        <input class="input-validation-error form-control" data-val="true" data-val-required="* Required" id="startDate" name="startDate" type="text" value=""> <span class="input-group-addon"><i class="fa fa-calendar"></i></span>

    </div>
</div>

CSS

/*!
 * Datepicker for Bootstrap
 *
 * Copyright 2012 Stefan Petre
 * Improvements by Andrew Rowls
 * Licensed under the Apache License v2.0
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 */
 .datepicker {
    padding: 4px;
    border-radius: 4px;
    direction: ltr;
    /*.dow {
		border-top: 1px solid #ddd !important;
	}*/
}
.datepicker-inline {
    width: 220px;
}
.datepicker.datepicker-rtl {
    direction: rtl;
}
.datepicker.datepicker-rtl table tr td span {
    float: right;
}
.datepicker-dropdown {
    top: 0;
    left: 0;
}
.datepicker-dropdown:before {
    content:'';
    display: inline-block;
    border-left: 7px solid transparent;
    border-right: 7px solid transparent;
    border-bottom: 7px solid #ccc;
    border-top: 0;
    border-bottom-color: rgba(0, 0, 0, 0.2);
    position: absolute;
}
.datepicker-dropdown:after {
    content:'';
    display: inline-block;
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    border-bottom: 6px solid #fff;
    border-top: 0;
    position: absolute;
}
.datepicker-dropdown.datepicker-orient-left:before {
    left: 6px;
}
.datepicker-dropdown.datepicker-orient-left:after {
    left: 7px;
}
.datepicker-dropdown.datepicker-orient-right:before {
    right: 6px;
}
.datepicker-dropdown.datepicker-orient-right:after {
    right: 7px;
}
.datepicker-dropdown.datepicker-orient-top:before {
    top: -7px;
}
.datepicker-dropdown.datepicker-orient-top:after {
    top: -6px;
}
.datepicker-dropdown.datepicker-orient-bottom:before {
    bottom: -7px;
    border-bottom: 0;
    border-top: 7px solid #999;
}
.datepicker-dropdown.datepicker-orient-bottom:after {
    bottom: -6px;
    border-bottom: 0;
    border-top: 6px solid #fff;
}
.datepicker > div {
    display: none;
}
.datepicker.days div.datepicker-days {
    display: block;
}
.datepicker.months div.datepicker-months {
    display: block;
}
.datepicker.years div.datepicker-years {
    display: block;
}
.datepicker table {
    margin: 0;
   ...

JavaScript

$('#month-group-container .input-group.date').datepicker({
    minViewMode: 1,
    autoclose: true,
}).on('changeDate', function (ev) {
    var endDate = new Date(ev.date);
    var endMonth = endDate.getMonth();
    var endYear = endDate.getFullYear();
    endMonth += 1;
    endDate = new Date(endYear, endMonth, 0);
    $(this).datepicker('setDate', endDate);
});