JS 把 Wed Jul 15 2015 00:00:00 GMT+0800 转换成2015-07-15

function strlen(str) {
            var len = 0;
            for (var i = 0; i < str.length; i++) {
                var c = str.charCodeAt(i);
                //单字节加1 
                if ((c >= 0x0001 && c <= 0x007e) || (0xff60 <= c && c <= 0xff9f)) {
                    len++;
                }
                else {
                    len += 2;
                }
            }
            return len;
        }
        function Todate(num) { //Fri Oct 31 18:00:00 UTC+0800 2008     Wed Jul 15 2015 00:00:00 GMT+0800
            num = num + "";
            var date = "";
            var month = new Array();
            month["Jan"] = 1; month["Feb"] = 2; month["Mar"] = 3; month["Apr"] = 4; month["May"] = 5; month["Jan"] = 6;
            month["Jul"] = 7; month["Aug"] = 8; month["Sep"] = 9; month["Oct"] = 10; month["Nov"] = 11; month["Dec"] = 12;
            var week = new Array();
            week["Mon"] = "一"; week["Tue"] = "二"; week["Wed"] = "三"; week["Thu"] = "四"; week["Fri"] = "五"; week["Sat"] = "六"; week["Sun"] = "日";
            
            str = num.split(" ");
            date = str[3] + "-";
            var count = strlen(month[str[1]]);
            var m = month[str[1]];
            if (count = 1) {
                m = "0" + month[str[1]];
            }
            date = date + m + "-" + str[2];
            return date;
        }

方法Todate(参数)  参数格式：Wed Jul 15 2015 00:00:00 GMT+0800