//獲取當前時間，格式YYYY-MM-DD
    function getNowFormatDate() {
        var date = new Date();
        var seperator1 = "-";
        var year = date.getFullYear();
        var month = date.getMonth() + 1;
        var strDate = date.getDate();
        if (month >= 1 && month <= 9) {
            month = "0" + month;
        }
        if (strDate >= 0 && strDate <= 9) {
            strDate = "0" + strDate;
        }
        var currentdate = year + seperator1 + month + seperator1 + strDate;
        return currentdate;
    }
 

當前時間減一天

function daysJian(){  
  var date = new Date();//獲取當前時間  
  date.setDate(date.getDate()-1);//設置天數 -1 天  
   var time = date.Format("yyyyMMdd");  
}  

js獲取當前時間，格式YYYY-MM-DD