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();