@Blog

        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;
        }