JSFiddle - React, Tailwind, and code Playground
JavaScript
var str = "20960229";
var showDate = new Date();
showDate.setFullYear(str.substring(0, 4))
showDate.setMonth(parseInt(str.substring(4, 6), 10) - 1)
showDate.setDate(str.substring(6, 8))
document.write(showDate)