JS 實現日期信息增加年數，月數，天數

function DateAdd(interval, number, date) {
            /*
            *   功能:實現JSScript的DateAdd功能.
            *   參數:interval,字符串表達式，表示要添加的時間間隔.
            *   參數:number,數值表達式，表示要添加的時間間隔的個數.
            *   參數:date,時間對象.
            *   返回:新的時間對象.
            *   var   now   =   new   Date();
            *   var   newDate   =   DateAdd( "d ",5,now);
            *---------------   DateAdd(interval,number,date)   -----------------
            */
            switch (interval) {
                case "y ":
                    {
                        date.setFullYear(date.getFullYear() + number);
                        return date;
                        break;
                    }
                case "q ":
                    {
                        date.setMonth(date.getMonth() + number * 3);
                        return date;
                        break;
                    }
                case "m ":
                    {
                        date.setMonth(date.getMonth() + number);
                        return date;
                        break;
                    }
                case "w ":
                    {
                        date.setDate(date.getDate() + number * 7);
                        return date;
                        break;
                    }
                case "d ":
                    {
                        date.setDate(date.getDate() + number);
                        return date;
                        break;
                    }
                case "h ":
                    {
                        date.setHours(date.getHours() + number);
                        return date;
                        break;
                    }
                case "m ":
                    {
                        date.setMinutes(date.getMinutes() + number);
                        return date;
                        break;
                    }
                case "s ":
                    {
                        date.setSeconds(date.getSeconds() + number);
                        return date;
                        break;
                    }
                default:
                    {
                        date.setDate(d.getDate() + number);
                        return date;
                        break;
                    }
            }
        }
    //調用
       var newDate = DateAdd("y ", 1, dtADate);

轉：http://blog.163.com/hehong0925@126/blog/static/13393333720141066026886/