<div id="datetimepicker1" class='input-group date' style="width:280px; height: 40px;">
    @Html.TextBox("DateStart", null, new { @class = "input-group date form-control add-on", @style = "height: 40px; width: 240px;" })
    <span class="add-on input-group-addon" style="height:40px;">
        <span class="glyphicon glyphicon-calendar"></span>
    </span>
</div>
<div id="datetimepicker2" class='input-group date' style="width:280px; height: 40px;">
    @Html.TextBox("DateEnd", null, new { @class = "input-group date form-control add-on", @style = "height: 40px; width: 240px;" })
    <span class="add-on input-group-addon" style="height:40px;">
        <span class="glyphicon glyphicon-calendar"></span>
    </span>
</div>


<script>
    $(function () {
        var newDate;
        var month;
        var dateen;

        $('#datetimepicker1').datetimepicker({
            language: 'ru',
            pickDate: true,
            pickTime: false,
            format: 'dd.MM.yyyy',
            autoclose: true,
            startDate: new Date()
        }).on('changeDate', function (ev) {
            newDate = new Date(ev.date)
            locale = "en-us",
            month = newDate.toLocaleString(locale, { month: "long" });
            console.log(month + " " + newDate.getDate().toString() + " " + newDate.getFullYear().toString());
            dateen = month.toString() + " " + newDate.getDate()+ " " + newDate.getFullYear()
        }).data('datepicker');
     
      $('#datetimepicker2').datetimepicker({
            language: 'ru',
            pickDate: true,
            pickTime: false,
            format: 'dd.MM.yyyy',
            //startDate: new Date("May 25 2014")
            startDate: new Date(dateen)
        }).on('changeDate', function (ev) {
            console.log(dateen)
        }).data('datepicker');
    }); 
</script>