js获取系统当前时间

   //js获取系统当前时间：YYYY-MM-DD

           var mydate=new Date(); 

   var currentMonth = mydate.getMonth()+1; 

           var currentDay = mydate.getDate();  

           var currentYear = mydate.getYear(); 

           var currentTime = currentYear + "-" + currentMonth + "-" + currentDay;