我以 24 小時(shí)格式從我的數(shù)據(jù)庫(kù)發(fā)送數(shù)據(jù)，但是當(dāng)我在前端使用它作為時(shí)間計(jì)數(shù)器時(shí)，輸出給出“無(wú)”。此外，當(dāng)我打印“plan_deactive_date”時(shí)，它以 12 小時(shí)格式顯示時(shí)間。那么，有沒(méi)有辦法將日期時(shí)間從 12 小時(shí)格式轉(zhuǎn)換為 24 小時(shí)格式？<script>// Set the date we're counting down tovar countDownDate = new Date("{{plan_deactive_date}}").getTime();// Update the count down every 1 secondvar x = setInterval(function() {  // Get today's date and time  var now = new Date().getTime();  // Find the distance between now and the count down date  var distance = countDownDate - now;  // Time calculations for days, hours, minutes and seconds  var days = Math.floor(distance / (1000 * 60 * 60 * 24));  var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));  var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));  var seconds = Math.floor((distance % (1000 * 60)) / 1000);  // Display the result in the element with id="demo"  document.getElementById("demo").innerHTML = days + "d " + hours + "h "  + minutes + "m " + seconds + "s ";  // If the count down is finished, write some text  if (distance < 0) {    clearInterval(x);    document.getElementById("demo").innerHTML = "Expired";  }}, 1000);</script>