javascript判断两个日期是否相等

var datenow = dt.getFullYear() + "-" + (dt.getMonth() + 1) + "-" + dt.getDate() + " 00:00:00";
            var endTime = new Date(Date.parse(datenow));
var endTime = new Date(Date.parse(datenow));
var startTime = new Date(Date.parse(datenow));

if (startTime.getTime() == endTime.getTime()) 
if (startTime- endTime==0)