Как на js конвертировать секунды в H:m:s?

function getHumanTime($seconds) {
        $sign = '';
        if($seconds < 0) {
            $sign = '-';
            $seconds = -$seconds;
        }
        $hours = floor($seconds / 3600);
        $seconds -= 3600 * $hours;
        $minutes = floor($seconds / 60);
        $seconds -= 60 * $minutes;
        return $sign . $hours . ':'
            . (($minutes < 10)? '0' : '') . $minutes . ':'
            . (($seconds < 10)? '0' : '') . (int) $seconds;
    }

const formatTime = seconds => [
  seconds / 3600 | 0,
  seconds / 60 % 60 | 0,
  seconds % 60,
].map(n => `${n}`.padStart(2, 0)).join(':');

function secToTime(num) {
    num = Number(num);
    var h = Math.floor(num / 3600);
    var m = Math.floor(num % 3600 / 60);
    var s = Math.floor(num % 3600 % 60);
    h = (h < 10 ? '0' : '') + h;
    m = (m < 10 ? '0' : '') + m;
    s = (s < 10 ? '0' : '') + s;
    return h + ':' + m + ':' + s;
}

alert(secToTime(70));