我一直在开发一个小时钟应用程序，它可以在加载时显示标准时间，并有一个切换按钮，可以将显示更改为军用时间。但是，我希望使用切换开关，能够在标准时间和军用时间之间来回切换。
如您所见，每次单击按钮，它就不切换到军用时间，还在标准时间和军用时间之间不断地来回走。
有什么办法解决吗？

const headClock = document.createElement("h2");
const dateDay = document.createElement("h2");
const time = document.createElement("h1");
const changeTimeFormat = document.createElement("button");
const div = document.createElement("div");

div.style.cssText = "text-align: center";
headClock.innerHTML = "A Simple Digital Clock";

const weekday = [
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday",
  "Friday",
  "Saturday",
];
const month = [
  "January",
  "February",
  "March",
  "April",
  "May",
  "June",
  "July",
  "August",
  "September",
  "October",
  "November",
  "December",
];

var isOppen = false;
let myInterval12 = setInterval(timeFor12, 1000);

function timeFor12() {
  isOppen = true;
  time.innerHTML = new Date().toLocaleString("ru-RU", {
    hour12: true,
    timeZone: "Asia/Riyadh",
    // hourCycle: `${hourCycle}`,
    hour: "2-digit",
    minute: "2-digit",
    second: "2-digit",
  });
}

function timeFor24() {
  isOppen = false;
  time.innerHTML = new Date().toLocaleString("ru-RU", {
    hour12: false,
    timeZone: "Asia/Riyadh",
    // hourCycle: `${hourCycle}`,
    hour: "2-digit",
    minute: "2-digit",
    second: "2-digit",
  });
}

const today = new Date();
dateDay.innerHTML = `${weekday[today.getDay()]}, ${
  month[today.getMonth()]
} ${today.getDay()}th ${today.getFullYear()}`;

changeTimeFormat.onclick = () => {
  console.log(isOppen)
  if (isOppen === true) {
    let myInterval24 = setInterval(timeFor24, 1000);
    clearInterval(myInterval24);
    setInterval(timeFor12, 1000);
    isOppen = false;
  } else if (isOppen === false){
    clearInterval(myInterval12);
    setInterval(timeFor24, 1000);
    isOppen = true;
  }
  // isOppen ? timeFor24() : timeFor12();
};

changeTimeFormat.innerHTML = `Switch to Military Time Format`;

div.appendChild(headClock);
div.appendChild(time);
div.appendChild(dateDay);
div.appendChild(changeTimeFormat);
document.body.appendChild(div);