その３２：グレゴリオ暦日付計算ライブラリ化

    this.ReformTable = {
      JP: { julianEnd: "1582-10-04", gregorianStart: "1582-10-14", reformDays: "10" },//日本
      GB: { julianEnd: "1752-09-02", gregorianStart: "1752-09-13", reformDays: "11" },//イギリス
      RU: { julianEnd: "1918-01-31", gregorianStart: "1918-02-13", reformDays: "13" },//ロシア
      GR: { julianEnd: "1923-02-15", gregorianStart: "1923-02-28", reformDays: "13" },//ギリシャ
      ...
    };

．．．省略．．．

＜script src="./javascripts/nas6lib/date.js"＞＜/script＞
＜script＞

function calc() {

// ######### TestCode Start #########

//イリーガルな初期化
const dtz = new N6LDate(2000,15.5,55.5,30).normalize();
console.log(dtz.toString());
// → 2001/05/10(Thu) 06:00:00.000

//日付加算
const dta = new N6LDate(1582,10,4).normalize();
console.log(dta.addDays(1).toString());
// → 1582/10/15(Fri) 00:00:00.000
const dtb = new N6LDate(2026,10,1,6).normalize();
console.log(dtb.addMonths(-1.5).toString());
// → 2026/08/16(Sun) 08:23:47.040
const dtc = new N6LDate(2026,12,15,6).normalize();
console.log(dtc.addYears(1.25).toString());
// → 2028/03/15(Wed) 19:30:00.000

//時刻加算
const dtd = new N6LDate(2026,7,15,12).normalize();
console.log(dtd.toString());
// → 2026/07/15(Wed) 12:00:00.000
console.log(dtd.addDays(0.75).toString());
// → 2026/07/16(Thu) 06:00:00.000
const dte = new N6LDate(2026,7,15,12).normalize();
console.log(dte.addHours(18).toString());
// → 2026/07/16(Thu) 06:00:00.000

//改暦デフォルト
const a = new N6LDate(1582,10,4).normalize();
const b = new N6LDate(1582,10,15).normalize();
console.log(b.diffDays(a)); // +1
console.log(a.diffDays(b)); // -1

//改暦日本
const jedjp = new N6LDate(1582,10,4,0,0,0,0,"JP").normalize();
const gsdjp = new N6LDate(1582,10,15,0,0,0,0,"JP").normalize();
console.log(gsdjp.diffDays(jedjp)); // +1
console.log(jedjp.diffDays(gsdjp)); // -1

//改暦イギリス
const jedgb = new N6LDate(1752,9,2,0,0,0,0,"GB").normalize();
const gsdgb = new N6LDate(1752,9,14,0,0,0,0,"GB").normalize();
console.log(gsdgb.diffDays(jedgb)); // +1
console.log(jedgb.diffDays(gsdgb)); // -1

//改暦ロシア
const jedru = new N6LDate(1918,1,31,0,0,0,0,"RU").normalize();
const gsdru = new N6LDate(1918,2,14,0,0,0,0,"RU").normalize();
console.log(gsdru.diffDays(jedru)); // +1
console.log(jedru.diffDays(gsdru)); // -1

//改暦ギリシャ
const jedgr = new N6LDate(1923,2,15,0,0,0,0,"GR").normalize();
const gsdgr = new N6LDate(1923,3,1,0,0,0,0,"GR").normalize();
console.log(gsdgr.diffDays(jedgr)); // +1
console.log(jedgr.diffDays(gsdgr)); // -1

//各種変換
const jp2000 = new N6LDate(2000,1,1,0,0,0,0,"JP").normalize();
console.log(jp2000.toString());      // 2000/01/01(Sat) 00:00:00.000
const jdjp2000 = jp2000.toJD();
console.log(jdjp2000);               // 2451544.5
const fmjdjp2000 = jp2000.fromJD(jdjp2000);
console.log(fmjdjp2000.toString());  // 2000/01/01(Sat) 00:00:00.000
const uxjp2000 = jp2000.toUNIX();
console.log(uxjp2000);               // 946684800
const fmuxjp2000 = jp2000.fromUNIX(uxjp2000);
console.log(fmuxjp2000.toString());  // 2000/01/01(Sat) 00:00:00.000

const ru2000 = new N6LDate(2000,1,1,0,0,0,0,"RU").normalize();
console.log(ru2000.toString());      // 2000/01/01(Sat) 00:00:00.000
const jdru2000 = ru2000.toJD();
console.log(jdru2000);               // 2451544.5
const fmjdru2000 = ru2000.fromJD(jdru2000);
console.log(fmjdru2000.toString());  // 2000/01/01(Sat) 00:00:00.000

//平年100年400年検証
const jp19000228 = new N6LDate(1900,2,28,0,0,0,0,"JP").normalize();
console.log(jp19000228.toString());      // 1900/02/28(Wed) 00:00:00.000
const jdjp19000228 = jp19000228.toJD();
console.log(jdjp19000228);               // 2415078.5
const fmjdjp19000228 = jp19000228.fromJD(jdjp19000228);
console.log(fmjdjp19000228.toString());  // 1900/02/28(Wed) 00:00:00.000
const jp19000229 = new N6LDate(1900,2,29,0,0,0,0,"JP").normalize();
console.log(jp19000229.toString());      // 1900/03/01(Thu) 00:00:00.000
const jdjp19000229 = jp19000229.toJD();
console.log(jdjp19000229);               // 2415079.5
const fmjdjp19000229 = jp19000229.fromJD(jdjp19000229);
console.log(fmjdjp19000229.toString());  // 1900/03/01(Thu) 00:00:00.000
const jp19000301 = new N6LDate(1900,3,1,0,0,0,0,"JP").normalize();
console.log(jp19000301.toString());      // 1900/03/01(Thu) 00:00:00.000
const jdjp19000301 = jp19000301.toJD();
console.log(jdjp19000301);               // 2415079.5
const fmjdjp19000301 = jp19000301.fromJD(jdjp19000301);
console.log(fmjdjp19000301.toString());  // 1900/03/01(Thu) 00:00:00.000

const jp20000228 = new N6LDate(2000,2,28,0,0,0,0,"JP").normalize();
console.log(jp20000228.toString());      // 2000/02/28(Mon) 00:00:00.000
const jdjp20000228 = jp20000228.toJD();
console.log(jdjp20000228);               // 2451602.5
const fmjdjp20000228 = jp20000228.fromJD(jdjp20000228);
console.log(fmjdjp20000228.toString());  // 2000/02/28(Mon) 00:00:00.000
const jp20000229 = new N6LDate(2000,2,29,0,0,0,0,"JP").normalize();
console.log(jp20000229.toString());      // 2000/02/29(Tue) 00:00:00.000
const jdjp20000229 = jp20000229.toJD();
console.log(jdjp20000229);               // 2451603.5
const fmjdjp20000229 = jp20000229.fromJD(jdjp20000229);
console.log(fmjdjp20000229.toString());  // 2000/02/29(Tue) 00:00:00.000
const jp20000301 = new N6LDate(2000,3,1,0,0,0,0,"JP").normalize();
console.log(jp20000301.toString());      // 2000/03/01(Wed) 00:00:00.000
const jdjp20000301 = jp20000301.toJD();
console.log(jdjp20000301);               // 2451604.5
const fmjdjp20000301 = jp20000301.fromJD(jdjp20000301);
console.log(fmjdjp20000301.toString());  // 2000/03/01(Wed) 00:00:00.000

const jp20010228 = new N6LDate(2001,2,28,0,0,0,0,"JP").normalize();
console.log(jp20010228.toString());      // 2001/02/28(Wed) 00:00:00.000
const jdjp20010228 = jp20010228.toJD();
console.log(jdjp20010228);               // 2451968.5
const fmjdjp20010228 = jp20010228.fromJD(jdjp20010228);
console.log(fmjdjp20010228.toString());  // 2001/02/28(Wed) 00:00:00.000
const jp20010229 = new N6LDate(2001,2,29,0,0,0,0,"JP").normalize();
console.log(jp20010229.toString());      // 2001/03/01(Thu) 00:00:00.000
const jdjp20010229 = jp20010229.toJD();
console.log(jdjp20010229);               // 2451969.5
const fmjdjp20010229 = jp20010229.fromJD(jdjp20010229);
console.log(fmjdjp20010229.toString());  // 2001/03/01(Thu) 00:00:00.000
const jp20010301 = new N6LDate(2001,3,1,0,0,0,0,"JP").normalize();
console.log(jp20010301.toString());      // 2001/03/01(Thu) 00:00:00.000
const jdjp20010301 = jp20010301.toJD();
console.log(jdjp20010301);               // 2451969.5
const fmjdjp20010301 = jp20010301.fromJD(jdjp20010301);
console.log(fmjdjp20010301.toString());  // 2001/03/01(Thu) 00:00:00.000

const jp2000715 = new N6LDate(2000,7,15).normalize();
console.log(jp2000715.getISOWeekDate());  // {isoYear: 2000, isoWeek: 29, isoWeekDay: 3}
const jp2010715 = new N6LDate(2010,7,15).normalize();
console.log(jp2000715.getISOTimeDuration(jp2010715));  // -P9Y11M28DT3H34M24.960S
console.log(jp2000715.getReformInfo());  //In UK, due to the calendar reform, the day following 1752-09-02 was 1752-09-14, and 11 days were skipped.
console.log(jp2000715.format("YYYY-MM-DD hh:mm:ss.SSS (W)")); // 2000-07-15 00:00:00.000 (Sat)
jp2000715.regionW = "JP";
console.log(jp2000715.format("YYYY年 MMMM月 DD日 (W)")); // 2000年 7月 15日 (土)

const jp2030915 = new N6LDate(2030,9,15,12).normalize();
console.log(jp2030915.toString());         //2030/09/15(Sun) 12:00:00.000
const uxjp2030915 = jp2030915.toUNIX(jp2030915);
console.log(uxjp2030915);                  //1915704000
const fmuxjp2030915 = jp2030915.fromUNIX(uxjp2030915);
console.log(fmuxjp2030915.toString());     //2030/09/15(Sun) 12:00:00.000
const ctuxjp2030915 = new N6LDate(uxjp2030915*1000).normalize();
console.log(ctuxjp2030915.toString());     //2030/09/15(Sun) 12:00:00.000

//シリアライズ
const dtSz = new N6LDate(2030, 9, 15, 12, 34, 56, 789).normalize();
dtSz.region = "JP";
const json = JSON.stringify(dtSz);          // toJSONが自動呼び出し
// → {"year":2030,"month":9,"day":15,...}
const restored = N6LDate.fromJSON(JSON.parse(json));
console.log(restored.toString());           // 2030/09/15(Sun) 12:34:56.789

const jp20150606 = new N6LDate(2015, 6, 6, 12, 34, 56, 789).normalize();
console.log(jp20150606.startOf("day").toString());    //2015/06/06(Sat) 00:00:00.000
console.log(jp20150606.startOf("month").toString());  //2015/06/01(Mon) 00:00:00.000
console.log(jp20150606.startOf("year").toString());   //2015/01/01(Thu) 00:00:00.000
console.log(jp20150606.startOf("week").toString());   //2015/06/01(Mon) 00:00:00.000
console.log(jp20150606.endOf("day").toString());      //2015/06/06(Sat) 23:59:59.999
console.log(jp20150606.endOf("month").toString());    //2015/06/30(Tue) 23:59:59.999
console.log(jp20150606.endOf("year").toString());     //2015/12/31(Thu) 23:59:59.999
console.log(jp20150606.endOf("week").toString());     //2015/06/07(Sun) 23:59:59.999

// ######### TestCode End #########

  var element = document.getElementById('REGION');
  var reg = element.value;

  var elm = document.getElementById('TXTY0');
  var y0 = Number(elm.value);
  elm = document.getElementById('TXTM0');
  var m0 = Number(elm.value);
  elm = document.getElementById('TXTD0');
  var d0 = Number(elm.value);

  elm = document.getElementById('TXTY1');
  var y1 = Number(elm.value);
  elm = document.getElementById('TXTM1');
  var m1 = Number(elm.value);
  elm = document.getElementById('TXTD1');
  var d1 = Number(elm.value);

  elm = document.getElementById('TXTDT');
  var dt = Number(elm.value);

  // 基準日（日付0）のインスタンス生成
  var val0 = new N6LDate(y0, m0, d0, 0, 0, 0, 0, reg).normalize();
  var val;
  var dadd = 0;
  var daddms = 0;

  if (0 ＜ y1) {
    // 日付1が有効な場合：
    // 「日付1 - 日付0」の差分日数に、入力された加算日数(dt)を足したものがトータルの加算日数
    var val1 = new N6LDate(y1, m1, d1, 0, 0, 0, 0, reg).normalize();
    dadd = val1.diffDays(val0) + dt;
    val = val0.addDays(dadd);
  } else {
    // 日付1が無効（未指定など）の場合：
    // 日付0を基準に加算日数(dt)のみを反映
    dadd = dt;
    val = val0.addDays(dadd);
    dadd += val.pastdays;
  }

  daddms = dadd * val0.DayMS;

  // 結果の画面反映
  elm = document.getElementById('TXTCL');
  elm.value = val.afterGregorian(val) ? "グレゴリオ暦" : "ユリウス暦";

  elm = document.getElementById('TXTYA');
  elm.value = val.ya;
  elm = document.getElementById('TXTMA');
  elm.value = val.ma;
  elm = document.getElementById('TXTDA');
  elm.value = val.da;

  elm = document.getElementById('TXTDTA');
  elm.value = dadd;
  elm = document.getElementById('TXTWKA');
  elm.value = val.weeks[Number(val.wk)];
  elm = document.getElementById('TXTMSA');
  elm.value = daddms;
}


function now() {
  var dt = new Date();
  var year = dt.getFullYear();
  var month = dt.getMonth() + 1; // getMonth() is 0-indexed, so add 1 for actual month
  var day = dt.getDate();
  var elm = document.getElementById('TXTY0');
  elm.value = year;
  elm = document.getElementById('TXTY1');
  elm.value = year;
  elm = document.getElementById('TXTM0');
  elm.value = month;
  elm = document.getElementById('TXTM1');
  elm.value = month;
  elm = document.getElementById('TXTD0');
  elm.value = day;
  elm = document.getElementById('TXTD1');
  elm.value = day;
}

function newyear() {
  elm = document.getElementById('TXTM0');
  elm.value = 1;
  elm = document.getElementById('TXTM1');
  elm.value = 1;
  elm = document.getElementById('TXTD0');
  elm.value = 1;
  elm = document.getElementById('TXTD1');
  elm.value = 1;
}

function cls(i) {
  var elm;
  if(i == 1) {
    elm = document.getElementById('TXTY0');
    elm.value = 1;
    elm = document.getElementById('TXTM0');
    elm.value = 1;
    elm = document.getElementById('TXTD0');
    elm.value = 1;
  }
  else {
    elm = document.getElementById('TXTY1');
    elm.value = -1;
    elm = document.getElementById('TXTM1');
    elm.value = 1;
    elm = document.getElementById('TXTD1');
    elm.value = 1;
  }
}

＜/script＞

．．．省略．．．

＜hr＞
＜br＞
日付0＜br＞
西暦(自動判別)＜input type="text" id="TXTY0" value="1"＞年　＜input type="text" id="TXTM0" value="1"＞月　＜input type="text" id="TXTD0" value="1"＞日＜br＞
日付1＜br＞
西暦(自動判別)＜input type="text" id="TXTY1" value="-1"＞年　＜input type="text" id="TXTM1" value="1"＞月　＜input type="text" id="TXTD1" value="1"＞日＜br＞
加算日数＜input type="text" id="TXTDT" value="0"＞日＜br＞
＜br＞
解答＜br＞
＜input type="text" id="TXTCL" value="ユリウス暦" disabled＞＜br＞
＜input type="text" id="TXTYA" value="1" disabled＞年　＜input type="text" id="TXTMA" value="1" disabled＞月　＜input type="text" id="TXTDA" value="1" disabled＞日＜br＞
曜日＜input type="text" id="TXTWKA" value="土" disabled＞曜日＜br＞
経過日数＜input type="text" id="TXTDTA" value="0" disabled＞日＜br＞
経過ミリ秒＜input type="text" id="TXTMSA" value="0" disabled＞ミリ秒＜br＞
＜br＞
＜input type="button" onclick="calc()"  value="計　算"＞　＜input type="button" onclick="now()"  value="現在日時"＞　＜input type="button" onclick="newyear()"  value="1月1日"＞
＜input type="button" onclick="cls(1)"  value="1クリア"＞　＜input type="button" onclick="cls(2)"  value="2クリア"＞＜br＞
＜hr＞

．．．省略．．．

  //var dt = new N6LDate().normalize();のように.normalize()を必ずつけてください
  constructor(ya, ma, da, ho, mo, so, ms, region = "JP")
  //クローン
  clone() 
  //N6LDays.pastdaysに仮置きするために1日のうちの時間成分の小数部を計算
  tempPDays(val)
  adjustTime(val)

  //通算日数取得(ユリウス暦・グレゴリオ暦自動処理)誤差含む
  //また正確な経過日数はnormalize()かadjustCalendar()後N6LDate.pastdayかN6LDate.msから取得してください
  calendarToDay(val) 

  //前日に変換
  suboneday(val)
  //日付解析
  parseDate(str)

  //週取得
  getWeek()
  //通算ミリセカンド取得チックタイム(元期1/1/1:0:0:0.000)
  getMS()
  //通算日数取得(元期1/1/1:0:0:0.000)
  getPDays()
  //時間取得
  getTime()
  //週番号
  getWeekNumber()
  //ISO Week Date（ISO 8601）
  getISOWeekDate()
  //ISO 8601 Time Duration（期間表記）
  getISOTimeDuration(target)
  //改暦情報
  getReformInfo(region = "GB", lng = "DEFAULT")

  //ユリウス暦グレゴリオ暦改暦
  afterGregorian(val)
  //当年閏年判定
  isLeap(val, flg = true)
  //月末判定
  isMonthEnd(val)
  //月末取得
  getMonthEnd(val, flg = true)
  //周期カウントアップ
  collection(y,ry,term)
  //通算閏年取得
  getLeap(val) 

  //this内容変更含む
  SetVal(val)

  // 通算日からグレゴリオ暦の日付オブジェクトを生成する
  gregorianDayToDate(targetDay, flg = true) 
  // ユリウス暦加算処理（通算日からユリウス暦の日付オブジェクトを生成）
  julianDayToDate(targetDay, flg = false) 
  // 日付調整処理（ユリウス暦・グレゴリオ暦自動処理）
  adjustCalendar(rh = null) 
  //[!!!通算ミリ秒!!!][日時週]正規化
  //this内容変更含む
  // 自身の日付・時間を正規化する（再帰を起こさない安全な実装）
  normalize()

  // 差分ミリセカンド取得 (this - target)
  diffMS(target)
  // 差分日数取得 (this - target)
  diffDays(target)
  // 差分構造体取得 (this - target)
  diffDuration(target)

  //比較演算
  isBefore(target) 
  isAfter(target) 
  isEqual(target, eps = 1e-6)

  // フォーマット出力 (例: "2026/07/29 04:55:04 水")
  toString(fmtsw = 0)
  static get N6LDATE_FMT_DEFAULT()  { return 0; }  // "2026/07/29(水) 04:55:04.123"
  static get N6LDATE_FMT_FULL()     { return 1; }  // "2026/07/29 04:55:04.123 (水)"
  static get N6LDATE_FMT_NW()       { return 2; }  // "2026/07/29 04:55:04.123"
  static get N6LDATE_FMT_DATE()     { return 3; }  // "2026/07/29(水)"
  static get N6LDATE_FMT_DATE_NW()  { return 4; }  // "2026/07/29"
  static get N6LDATE_FMT_ISO()      { return 5; }  // "2026-07-29(水) T 04:55:04.123 Z"
  static get N6LDATE_FMT_ISO_W()    { return 6; }  // "2026-07-29 T 04:55:04.123 Z (水)"
  static get N6LDATE_FMT_ISO_NW()   { return 7; }  // "2026-07-29 T 04:55:04.123 Z"
  static get N6LDATE_FMT_ISO_D()    { return 8; }  // "2026-07-29(水)"
  static get N6LDATE_FMT_ISO_D_NW() { return 9; }  // "2026-07-29"
  // カスタムフォーマット出力
  // 例: date.format("YYYY-MM-DD hh:mm:ss.SSS (W)")
  format(pattern)

  // Dateオブジェクト出力
  toDate() 
  // Temporalオブジェクト出力
  toTemporal()
  //現在日時でクリエイト
  Now()

  // ユリウス日
  toJD()
  fromJD(rh)

  // 修正ユリウス日
  toMJD()
  fromMJD(rh)

  // ユニックス時間
  toUNIX()
  fromUNIX(rh)

  // ユニックス時間ミリ秒
  toUNIXms()
  fromUNIXms(rh)

  //シリアライズ
  //const dt = new N6LDate(2030, 9, 15, 12, 34, 56, 789).normalize();
  //dt.region = "JP";
  //const json = JSON.stringify(dt);          // toJSONが自動呼び出し
  // → {"year":2030,"month":9,"day":15,...}
  //const restored = N6LDate.fromJSON(JSON.parse(json));
  //console.log(restored.toString());         // 2030/09/15(Sun) 12:34:56.789
  toJSON()
  static fromJSON(json)

  startOf(unit)
  endOf(unit)
 
  // 各種加算//引数を少数を含む経過日にしてadjustCalendarを叩くだけ
  addYears(rh)
  addMonths(rh)
  addDays(rh) 
  addHours(rh)
  addMinutes(rh)
  addSeconds(rh)
  addMSs(rh)