Calculate days difference between two Dates on jQuery DatePicker selection using C# and VB.Net in ASP.Net

Hi sthsyed,

Check this example. Now please take its reference and correct your code.

HTML

<div>
    From Date: &nbsp;<input id="txtFDFromDate" runat="server" class="datepicker" clientidmode="Static"
        type="text" />
    <br />
    From Date: &nbsp;<input id="txtFDToDate" runat="server" class="datepicker" clientidmode="Static"
        type="text" />
    <br />
    Difference: &nbsp;<asp:TextBox ID="txtDifference" runat="server" />
    <br />
    <asp:Button ID="btnDifference" Text="Difference" runat="server" OnClick="Difference" Style="display: none" />
    <link rel="Stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.9.2/themes/ui-darkness/jquery-ui.css" />
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
    <script type="text/javascript">
        $(function () {
            $("#txtFDFromDate").datepicker({ dateFormat: "dd/mm/yy" });
            $("#txtFDToDate").datepicker({
                dateFormat: "dd/mm/yy",
                onSelect: function () { $('#btnDifference').trigger("click"); }
            });
        });
    </script>
</div>

C#

protected void Difference(object sender, EventArgs e)
{
    DateTime FDFromDate = DateTime.ParseExact(Request.Form["txtFDFromDate"], "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
    DateTime FDToDate = DateTime.ParseExact(Request.Form["txtFDToDate"], "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
    txtDifference.Text = (FDFromDate - FDToDate).TotalDays.ToString();
}

VB.Net

Protected Sub Difference(ByVal sender As Object, ByVal e As EventArgs)
    Dim FDFromDate As DateTime = DateTime.ParseExact(Request.Form("txtFDFromDate"), "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture)
    Dim FDToDate As DateTime = DateTime.ParseExact(Request.Form("txtFDToDate"), "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture)
    txtDifference.Text = (FDFromDate - FDToDate).TotalDays.ToString()
End Sub

Screenshot