js获取30天前的日期

可以使用以下代码获取30天前的日期：

var today = new Date();
var thirtyDaysAgo = new Date(today.getTime() - 30 * 24 * 60 * 60 * 100);
var year = thirtyDaysAgo.getFullYear();
var month = thirtyDaysAgo.getMonth() + 1;
var day = thirtyDaysAgo.getDate();
var thirtyDaysAgoStr = year + "-" + month + "-" + day;
console.log(thirtyDaysAgoStr);