JSFiddle - React, Tailwind, and code Playground

HTML

Month: <input type="text" id="em">
Year: <input type="text" id="ey">

JavaScript

var expMonth = "01";
    var expYear = "19";

    var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];

    $("#em").val(monthNames[+expMonth-1]);
    $("#ey").val("20"+expYear);