public ActionResult GetArrayofDates()
            {
                DateTime[] d = new DateTime[]
                {
                    new DateTime(2019,9,27),
                    new DateTime(2019,9,25),
                    new DateTime(2015,7,27),
                    new DateTime(2019,5,5)
                };

                return View(d);
            }

@{
    ViewBag.Title ="GetArrayofDates";
}
<link href="~/Content/themes/base/jquery-ui.min.css" rel="stylesheet" />
<style>
    .highlight {
        background-color: #ff0000 !important;
        color: #ffffff !important;

    }
    .nothighlight{
        background-color:#fff7f7;
        color:#000000;
    }
</style>
GetArrayofDates
@{

    for (int i = 0; i < Model.Length; i++)
    {
        @Model[i]
    }
}



<script src="~/Scripts/jquery-3.3.1.min.js">
<script src="~/Scripts/jquery-ui-1.12.1.js">




    var dates = []

@foreach (var item in Model)
{

    //@: allow you to write javascritp/hhtml code inside c# code which you specific using @ which allow write c# inside javascrpit/html
    @:dates.push('@item.ToString("yyyy-M-dd")');
}
    console.log(dates);
    console.log(dates["0"])

    $("#calandar").datepicker({
        todayHighlight: true,
        changeYear: true,
        changeMonth: true,
        minDate: new Date(2010,1,1),
        beforeShowDay: function (date) {

            var calender_date = date.getFullYear() + '-' + (date.getMonth() + 1) + '-' + ('0' + date.getDate()).slice(-2);
            console.log(calender_date)
            var search_index = $.inArray(calender_date, dates);

            if (search_index > -1) {
                return [true,'highlight','Employee Worked on this day.' ];
            } else {
                return [true, 'nothighlight', 'Employee did not Work on this day.'];
            }

        }
    });