I need to check for 5 years of history using jQuery.

I need to check for 5 years of history using jQuery.

Hello jQuery gurus. I'm currently developing a form where our clients are filling out their home and employment address information and I need to check their "from" and "to" dates to see if they're giving us 5 years of address history. I know there have been similar questions asked on here before, but I can't seem to get anything to work for me. So here's my code that I have so far.

$("#EmploymentHistoryStartDate").blur(function () { //just using .blur for now for testing purposes.
  var startDate = $(this).val();
  var customDate = new Date();
  var todaysDate = (customDate.getMonth() + 1) + "/" + customDate.getDate() + "/" + customDate.getFullYear();
  var fiveYDate = todaysDate.setDate(todaysDate.getDate() - 1827);
//1827 days is approximately 5 years; give or take a day or two for things like leap year.
if (fiveYDate < startDate) {
    alert("Not enough address history. Please enter another address.");
}

So then there will be a link button that says "Add New Address" that they can click to roll down another set of address boxes. I did this years ago on the old form and it worked good, but I can't seem to get it to work now.
Using bootstrap and latest jQuery (3.2.1) in an ASP.Net MVC app. Thanks in advance.