add month to a date moment js

Question

I am trying to add no of months to a given date using js. fd_start_date has the start date, but moment.js returns "Invalid Date". I am using date picker to select date in format YYYY-MM-DD.

$('#fd_start_date').click(function () {
            var start_date=$("#fd_start_date").val();
            var no_of_months=$("#fd_duration").val();
            var currentDate = moment(start_date);
            var future_date = moment(currentDate).add(no_of_months, 'months');
            console.log(future_date);

        });

Answer 1

Works for me if I change to on input and have a value in the month field

$('#fd_start_date, #fd_duration').on("input",function() {
  var start_date = $("#fd_start_date").val();
  if (start_date) {
    var no_of_months = $("#fd_duration").val();
    var currentDate = moment(start_date);
    var future_date = moment(currentDate).add(no_of_months, 'months');
    console.log(future_date);
  }  
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>

<input type="date" id="fd_start_date" /><input type="number" id="fd_duration" value="1" />