var date = "2018-11-30 23:59:59";
//var date = "2018-11-30";
var addNum = "3";
var num = parseInt(addNum);
var d=new Date(date);
var thisMonth = d.getMonth()+1;
var thisYear = d.getFullYear();
var thisDay = d.getDate();
var thisHour = d.getHours();
var thsiMinu = d.getMinutes();
var thisSecon = d.getSeconds();
var addCount = thisMonth + num;
var diffMonthCount = parseInt(addCount/12); //取整