Invalid Date

16-10-22 is an invalid date format from JS perspective. Such format will always give you invalid date format.

You need to parse it in yyyy-mm-dd format first before passing it to new Date() method.

var date1=new Date().getFullYear()+"-"+theDate.split("-")[1]+"-"+theDate.split("-")[0];

if (ddlStatus == "Return Delivered" && (theDate.trim() === "" || isNaN(new Date(date1).getTime()))) {
               bootbox.alert({
                   size: 'small',
                   title: 'Error!',
                   message: 'Invalid Date'
               });
               valid = false;
}

Hello

You need to convert to datetime before pass to new Date() please check below code

CultureInfo provider = CultureInfo.InvariantCulture;  
DateTime dateTime = DateTime.ParseExact("16-10-22", "dd-mm-yy", provider);