@Blog

function lt2et(date) {
  // UNIX時間（秒）を取得
  const ut = date.getTime() / 1000;

  // エオルゼア時間1/1/1 00:00:00から経過した秒数
  const et_seconds = (ut * 60.0) / 175.0;

  // 各エオルゼア単位を計算
  const et_hours = ut / 175.0;
  const et_days = et_hours / 24.0;
  const et_months = et_days / 32.0;

  const et_year = et_months / 12.0 + 1.0;
  const et_month = (et_months % 12.0) + 1.0;
  const et_date = (et_days % 32.0) + 1.0;
  const et_hour = et_hours % 24.0;
  const et_minute = et_seconds % 60.0;

  return {
    year: Math.floor(et_year),
    month: Math.floor(et_month),
    date: Math.floor(et_date),
    hour: Math.floor(et_hour),
    minute: Math.floor(et_minute),
  };
}
setInterval(() => {
  let date;

  date = new Date(); // 現在時刻

  const et = lt2et(date);

  // 出力（例: 0001-01-01 00:00）
  document.getElementById("output").textContent = `
  ${et.month.toString().padStart(2, "0")}-${et.date
    .toString()
    .padStart(2, "0")} ${et.hour.toString().padStart(2, "0")}:${et.minute
    .toString()
    .padStart(2, "0")}
`;
}, 0);

<div class="clock">
    <div class="hand hour-hand"></div>
    <div class="hand minute-hand"></div>
    <div class="hand second-hand"></div>
    <div class="center-clock"></div>
</div>

.clock {
  /* width: 200px;
  height: 200px;
  border: 2px solid rgb(226, 226, 226); */
  border-radius: 50%;
}

.hand {
  position: absolute;
  bottom: 50%;
  left: 50%;
  transform-origin: bottom;
  background: #333!important;
}

.hour-hand {
  width: 4px;
  height: 60px;
  background: #333!important;;
}

.minute-hand {
  width: 3px;
  height: 80px;
  background: #666!important;;
}

.second-hand {
  width: 2px;
  height: 90px;
  background: rgb(94, 93, 93)!important;;
}

.center-clock {
  width: 10px;
  height: 10px;
  background: rgb(95, 95, 95)!important;;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 4;
}

        function updateClock() {
            const now = new Date();
            const hours = now.getHours();
            const minutes = now.getMinutes();
            const seconds = now.getSeconds();

            // 角度の計算
            const hourDeg = (hours % 12 + minutes / 60) * 30; // 12時間で360度
            const minuteDeg = (minutes + seconds / 60) * 6; // 60分で360度
            const secondDeg = seconds * 6; // 60秒で360度

            // 針の回転
            document.querySelector('.hour-hand').style.transform = `translateX(-50%) rotate(${hourDeg}deg)`;
            document.querySelector('.minute-hand').style.transform = `translateX(-50%) rotate(${minuteDeg}deg)`;
            document.querySelector('.second-hand').style.transform = `translateX(-50%) rotate(${secondDeg}deg)`;
        }

        // 初回実行
        updateClock();
        // 1秒ごとに更新
        setInterval(updateClock, 1000);

        function updateCountdown() {
            const now = new Date();
            const nextNewYear = new Date(now.getFullYear() + 1, 0, 1, 0, 0, 0); // 次の年の1月1日0時0分0秒
            const diff = nextNewYear - now; // ミリ秒差

            if (diff > 0) {
                const days = Math.floor(diff / (1000 * 60 * 60 * 24));
                const hours = Math.floor((diff % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
                const minutes = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
                const seconds = Math.floor((diff % (1000 * 60)) / 1000);

                // 表示を更新
                document.getElementById("countdown").innerText =
                    kanji(`${days}日 ${hours}時間 ${minutes}分 ${seconds}秒`);
            } else {
                document.getElementById("countdown").innerText = "明けましておめでとうございます！";
            }
        }

        // 初回呼び出しと1秒ごとの更新
        updateCountdown();
        setInterval(updateCountdown, 1000);
        function kanji(str){
            let oo = [{'kanji':'零'},{'kanji':'壱'},{'kanji':'弐'},{'kanji':'参'},{'kanji':'肆'},{'kanji':'伍'},{'kanji':'陸'},{'kanji':'漆'},{'kanji':'捌'},{'kanji':'玖'}];
            oo.forEach((o,index)=>{
                str = str.replace(new RegExp(index, "g"),o.kanji);
            });
            return str;
        }