JSFiddle - React, Tailwind, and code Playground
JavaScript
var startDate = "2012-05-02";
var endDate = "2012-05-03";
var startDateSplit = startDate.split('-');
var newStartDate = new Date(startDateSplit[0], startDateSplit[1]-1, startDateSplit[2]);
var endDateSplit = endDate.split('-');
var newEndDate = new Date(endDateSplit[0], endDateSplit[1]-1, endDateSplit[2]);
alert(startDateSplit.getTime() - endDateSplit.getTime())