Super simple js to calculate the difference between two times in days

Look directly at the example:

n1 = "2021-10-25 18:29:59"
var dateBegin = new Date(n1); //可以把n1转化成“Mon Oct 25 2021 18:29:59 GMT+0800 (中国标准时间)”
var date = new Date(); //获取当前时间
var result = date.getTime() - dateBegin.getTime(); 
var joinTime = Math.floor(result / (24 * 3600 * 1000)); 
console.log(joinTime )