JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" value="2013-09-02" id="birth_date"/>

JavaScript

var birth_date = document.getElementById('birth_date').value;
alert(birth_date);
var day = new Date(Date.parse(birth_date));

document.getElementById('birth_date').value = day.getDate() + "-" + day.getMonth() + "-" +  day.getFullYear();