js对日期增减天数的函数

    function addDays(date, num) {

        var targetday_milliseconds = date.getTime() + 1000 * 60 * 60 * 24 * num;

 

        date.setTime(targetday_milliseconds);  

 

        var tYear = date.getFullYear();

        var tMonth = date.getMonth();

        var tDate = date.getDate();

        tMonth = doHandleMonth(tMonth + 1);

        tDate = doHandleMonth(tDate);

        tHour = date.getHours();

        tMinute = date.getMinutes();

        tSecond = date.getSeconds();

        tHour = doHandleMonth(date.getHours());

        tMinute = doHandleMonth(date.getMinutes());

        tSecond = doHandleMonth(date.getSeconds());

 

        return tYear + "/" + tMonth + "/" + tDate + " " + tHour + ":" + tMinute + ":" + tSecond;

    }

 

    doHandleMonth : function(month){ 

        var m = month; 

        if(month.toString().length == 1){ 

            m = "0" + month; 

        } 

        return m; 

    }