js将时间戳装换成日期格式

13位时间戳改为yyyy-MM-dd HH-mm-ss 格式 
目标时间戳：1516324500000

formatDateTime (unix) { // 转换时间戳

            var date = new Date(unix)// 时间戳为10位需*1000，时间戳为13位的话不需乘1000

            var Y = date.getFullYear() + '-'

            var M = (date.getMonth() +  <  ? '' + (date.getMonth() + ) : date.getMonth() + ) + '-'

            var D = date.getDate() + ' '

            var h = date.getHours() + ':'

            var m = date.getMinutes() + ':'

            var s = date.getSeconds()

            return Y + M + D + h + m + s

        }

//将时间戳改为yyyy-MM-dd HH-mm-ss

    function formatDateTime(unix) {

        var now = new Date(parseInt(unix) * 1);

        now =  now.toLocaleString().replace(/年|月/g, "-").replace(/日/g, " ");

        if(now.indexOf("下午") > 0) {

            if (now.length == 18) {

                var temp1 = now.substring(0, now.indexOf("下午"));   //2014/7/6

                var temp2 = now.substring(now.indexOf("下午") + 2, now.length);  // 5:17:43

                var temp3 = temp2.substring(0, 1);    //  5

                var temp4 = parseInt(temp3); // 5

                temp4 = 12 + temp4;  // 17

                var temp5 = temp4 + temp2.substring(1, temp2.length); // 17:17:43

                now = temp1 + temp5; // 2014/7/6 17:17:43

                now = now.replace("/", "-"); //  2014-7/6 17:17:43

                now = now.replace("/", "-"); //  2014-7-6 17:17:43

            }else {

                var temp1 = now.substring(0, now.indexOf("下午"));   //2014/7/6

                var temp2 = now.substring(now.indexOf("下午") + 2, now.length);  // 5:17:43

                var temp3 = temp2.substring(0, 2);    //  5

                if (temp3 == 12){

                    temp3 -= 12;

                }

                var temp4 = parseInt(temp3); // 5

                temp4 = 12 + temp4;  // 17

                var temp5 = temp4 + temp2.substring(2, temp2.length); // 17:17:43

                now = temp1 + temp5; // 2014/7/6 17:17:43

                now = now.replace("/", "-"); //  2014-7/6 17:17:43

                now = now.replace("/", "-"); //  2014-7-6 17:17:43

            }

        }else {

            var temp1 = now.substring(0,now.indexOf("上午"));   //2014/7/6

            var temp2 = now.substring(now.indexOf("上午")+2,now.length);  // 5:17:43

            var temp3 = temp2.substring(0,1);    //  5

            var index = 1;

            var temp4 = parseInt(temp3); // 5

            if(temp4 == 0 ) {   //  00

                temp4 = "0"+temp4;

            }else if(temp4 == 1) {  // 10  11  12

                index = 2;

                var tempIndex = temp2.substring(1,2);

                if(tempIndex != ":") {

                    temp4 = temp4 + "" + tempIndex;

                }else { // 01

                    temp4 = "0"+temp4;

                }

            }else {  // 02 03 ... 09

                temp4 = "0"+temp4;

            }

            var temp5 = temp4 + temp2.substring(index,temp2.length); // 07:17:43

            now = temp1 + temp5; // 2014/7/6 07:17:43

            now = now.replace("/","-"); //  2014-7/6 07:17:43

            now = now.replace("/","-"); //  2014-7-6 07:17:43

        }

        return now;

    };

    alert(formatDateTime(1516324500000));