JSFiddle - React, Tailwind, and code Playground

HTML

<input id="today" type="text" />
<input id="future" type="text" />

JavaScript

$(document).ready(function () {
    $('#today').keyup(function () {
        var today = new Date($(this).val());
        if (today != NaN) {
            var dd = today.getDate();
            var mm = today.getMonth();
            var y = today.getFullYear();
            $('#future').val(dd + '/' + mm + '/' + (parseInt(y)+1));
        }
    });
});