Get Date with second in DateTimePicker using DynDateTime jQuery Plugin in ASP.Net

I will be selecting the date using data picker and after selecting the date i need to get the date in mm/dd/yyyy and hh:mm:ss with my below code i am able to acheive thatbut the problem is if it is evening 6:10 i am getting 18:10 only thing is i am  not getting 18:10:00 and if it is 18:10:01................. 18:10:59 i am getting them but again if it is 18:11:00 i am getting only 18:11 but i need to get along with 00 seconds also

I am able to get the date with mm/dd/yyyy hh:mm:ss using this below code

string todaydatenew = todaydate.ToString("MM/dd/yyyy hh:mm:ss");

but using this below code i am not getting seconds

EndDate = ViewState["ToDate"].ToString();
DateTime end = DateTime.Parse(EndDate);
EndDate = Request.Form[txtEndDate.UniqueID];
DateTime end = DateTime.Parse(EndDate);

<script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
<script src="Scripts/jquery.dynDateTime.min.js" type="text/javascript"></script>
<script src="Scripts/calendar-en.min.js" type="text/javascript"></script>
<link href="Styles/calendar-blue.css" rel="stylesheet" type="text/css" />
<script type="text/javascript">
    $(document).ready(function () {
        DatePic();
    });
    function DatePic() {
        $("#<%=txtStartDate.ClientID %>").dynDateTime({
            showsTime: true,
            ifFormat: "%m/%d/%y %H:%M",
            daFormat: "%l;%M %p, %e %m,  %Y",
            align: "BR",
            electric: false,
            singleClick: true,
            displayArea: ".siblings('.dtcDisplayArea')",
            button: ".next()",
        });
        $("#<%=txtEndDate.ClientID %>").dynDateTime({
            showsTime: true,
            ifFormat: "%m/%d/%y %H:%M",
            daFormat: "%l;%M %p, %e %m,  %Y",
            align: "BR",
            electric: false,
            singleClick: true,
            displayArea: ".siblings('.dtcDisplayArea')",
            button: ".next()"
        });
 
    }
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    if (prm != null) {
        prm.add_endRequest(function (sender, e) {
            if (sender._postBackSettings.panelsToUpdate != null) {
                DatePic();
            }
        });
    };
</script>
<asp:TextBox ID="txtEndDate" runat="server" ReadOnly="True" Visible="true" Width="250px" onchange="checktoDate()" CssClass="txtbx"></asp:TextBox