alert(new Date("2004/3/12"));
alert(new Date());
alert((new Date() - new Date("2004/3/12"))/1000/60/60/24);
alert((new Date(new Date().getYear(),new Date().getMonth(),new Date().getDate()) - new Date("2004/3/12"))/1000/60/60/24);
alert(new Date());
alert((new Date() - new Date("2004/3/12"))/1000/60/60/24);
alert((new Date(new Date().getYear(),new Date().getMonth(),new Date().getDate()) - new Date("2004/3/12"))/1000/60/60/24);
var c_date="2004"+"/"+"03"+"/"+"12";
var oldDay = new Date(c_date);
var today = new Date();
var num = today-oldDay;
var dni = Math.floor(num / (1000 * 60 * 60 * 24));
alert("相差"+dni+"天")
</script>