check date with javascript

Question

I have a javascript to verify dates input and enable a submit button if conditions are met. it is working only if sdate is today. what is wrong?

 

<div class="row no-gutters" onchange="checkDate()">
    <div class="col-md-2">
       <label for="PTWContent.StartDate" class="form-control badge-primary">2. Start Date</label>
       <input asp-for="PTWContent.StartDate" class="form-control" id="sdate" />
       <span id="msg1" class="text-danger"></span>
     </div>
     <div class="col-md-2">
       <label for="PTWContent.EndDate" class="form-control badge-primary">3. End Date</label>
       <input asp-for="PTWContent.EndDate" class="form-control" id="edate" />
       <span id="msg2" class="text-danger"></span>
     </div>
</div>

<div class="col-md-12 d-flex justify-content-center">
   <button id="btnSubmit">Save</button>
</div>

<script>
   function checkDate() {
     var msg1 = ""; var msg2 = "";
     var startDate = new Date($('#sdate').val());
     var today = new Date();
   if (startDate.toLocaleDateString() > today.toLocaleDateString() || startDate.toLocaleDateString() == today.toLocaleDateString()) {
                $("#edate").attr("disabled", false);
                var endDate = new Date($('#edate').val());
                if (startDate.toLocaleDateString() < endDate.toLocaleDateString() || startDate.toLocaleDateString() == endDate.toLocaleDateString()) {
                    $("#btnSubmit").attr("disabled", false);
                }
                else {
                    msg2 = msg2 + "Due Date cannot be before Start Date";
                    $("#btnSubmit").attr("disabled", true);
                }
            }
            else {
                msg1 = msg1 + "Start Date cannot be in the past";
                $("#btnSubmit").attr("disabled", true);
                $("#edate").attr("disabled", true);
            }

            $("#msg1").text(msg1);
            $("#msg2").text(msg2);

        }
    </script>