// あなたの誕生日 const yourBirthDay = { year: 1983, month: 2, date: 15 }; // Dateインスタンスに変換 const birthDate = new Date(yourBirthDay.year, yourBirthDay.month - 1, yourBirthDay.date); // 文字列に分解 const y2 = birthDate.getFullYear().toString().padStart(4, '0'); const m2 = (birthDate.getMonth() + 1).toString().padStart(2, '0'); const d2 = birthDate.getDate().toString().padStart(2, '0'); // 今日の日付 const today = n