怎么取得已知时间的下一天

//得到已知日期的下一天
function gettomorrow(date){ //date格式为2013-10-10格式
date=date.split("-");
var date=new Date(date[0],date[1],date[2]);
//alert(date);
var yesterday_milliseconds=date.getTime()+1000*60*60*24;
var yesterday = new Date();
yesterday.setTime(yesterday_milliseconds);

var strYear = yesterday.getFullYear();
var strDay = yesterday.getDate();
var strMonth = yesterday.getMonth()+1;
if(strMonth<10)
{
strMonth="0"+strMonth;
}
datastr = strYear+"-"+strMonth+"-"+strDay;
return datastr;
}