Javascript倒计时，＆＃34; HOUR＆＃34;格式

Question

我无法在2位数内进行小时转换。目前的产出将包括整个小时，它不包括日期。如果你运行它，你会更好地了解它。在控制台中尝试timer(7.543e+7);。

let countdown;
const timerDisplay=document.querySelector('.time_left');
function timer(seconds){
const now= Date.now();
const then=now+seconds*1000;
displayTimeLeft(seconds);

countdown= setInterval(()=>{
    const secondsLeft= Math.round((then-Date.now())/1000);
    if(secondsLeft<0){
        clearInterval(countdown);
        return;
    }
    displayTimeLeft(secondsLeft);
},1000);
}   
function displayTimeLeft(seconds){
    const days=Math.floor(seconds/(24*60*60));
    const hours=Math.floor(seconds/3600);
    const minutes=Math.floor((seconds - (hours * 3600)) / 60);
    const remainderSeconds=seconds%60;
  const display = `${days}:${hours}:${minutes}:${remainderSeconds < 10 ? '0' : '' }${remainderSeconds}`;
    document.title= display;
    timerDisplay.textContent= display;
}

输出：enter image description here

输出应该是[873:22:27:53]。