요일을 구해서 저장하려고합니다

<div id="autosave_wrapper" class="write_div">

            <span>출근날짜</span>

            <input type="text" name="wr_subject" value="<?php echo $subject ?>" id="wr_subject" required class="datepicker info_input required" size="12" placeholder="출근날짜">

        </div>

        <script>

            $(document).ready(function() {

                $("#wr_subject").datepicker({

                    dateFormat: "yy-mm-dd",

                    onSelect: function(dateText, inst) {

                        var selectedDate = new Date(dateText);

                        var daysOfWeek = ["일", "월", "화", "수", "목", "금", "토"];

                        var dayOfWeek = daysOfWeek[selectedDate.getDay()];

 

                        $("#wr_16").val(dayOfWeek);//wr_16에 저장

                        alert(dayOfWeek);//요일은 나오는데...

                    }

                });

            });

        </script>