웹페이지에 누적 실행 시간을 추가하는 JavaScript 코드

function secondToDate(second) {
    if (!second) {
        return 0;
    }
    var time = new Array(0, 0, 0, 0, 0);
    if (second >= 365 * 24 * 3600) {
        time[0] = parseInt(second / (365 * 24 * 3600));
        second %= 365 * 24 * 3600;
    }
    if (second >= 24 * 3600) {
        time[1] = parseInt(second / (24 * 3600));
        second %= 24 * 3600;
    }
    if (second >= 3600) {
        time[2] = parseInt(second / 3600);
        second %= 3600;
    }
    if (second >= 60) {
        time[3] = parseInt(second / 60);
        second %= 60;
    }
    if (second > 0) {
        time[4] = second;
    }
    return time;
}

function setTime() {
    var create_time = Math.round(new Date(Date.UTC(2017, 04, 18, 2, 0, 0)).getTime() / 1000);
    var timestamp = Math.round((new Date().getTime() + 8 * 60 * 60 * 1000) / 1000);
    currentTime = secondToDate((timestamp - create_time));
    currentTimeHtml = currentTime[0] + '年 ' + currentTime[1] + '天 ' + currentTime[2] + '时 ' + currentTime[3] + '分 ' + currentTime[4] + '秒 ';
    document.getElementById("htmer_time").innerHTML = currentTimeHtml;
}
setInterval(setTime, 1000);