DateTime.ParseExact Error: String was not recognized as a valid DateTime

String was not recognized as a valid DateTime.

Javascript

<script type="text/javascript">
    $(document).ready(function () {
        $(function () {
            alert("time");
            var d = new Date().getDate();
            var m = new Date().getMonth() + 1; // JavaScript months are 0-11
            var y = new Date().getFullYear();
            // $("[id$=txtdate]").val(d + "/" + m + "/" + y);
            $("[id$=txtdate]").val(y + "/" + m + "/" + d);
            $("[id$=txtdate]").datepicker({ weekStart: 1, dateFormat: 'yyyy/mm/dd' });
        });
    });
    </script>

 Design Page

<asp:TextBox ID="txtdate" runat="server" type='text' value="{{date | date:'yyyy-MM-dd'}}"  placeholder="DateTime" class="form-control col-sm 3"></asp:TextBox>     

 C# Coding

objSchema.TimeStamp = DateTime.ParseExact(txtdate.Text, "yyyy/dd/MM", null);