javascript倒计时(d:h:m:s)

// 设置目标时间
var targetDate = new Date("2022-01-01 00:00:00");

// 更新倒计时函数
function updateCountdown() {
  var currentDate = new Date();
  var timeDifference = targetDate - currentDate;

  // 计算剩余的天、小时、分钟和秒
  var days = Math.floor(timeDifference / (1000 * 60 * 60 * 24));
  var hours = Math.floor((timeDifference % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
  var minutes = Math.floor((timeDifference % (1000 * 60 * 60)) / (1000 * 60));
  var seconds = Math.floor((timeDifference % (1000 * 60)) / 1000);

  // 更新倒计时显示
  document.getElementById("countdown").innerHTML = days + "d:" + hours + "h:" + minutes + "m:" + seconds + "s";

  // 判断是否到达目标时间
  if (timeDifference < 0) {
    clearInterval(countdownInterval);
    document.getElementById("countdown").innerHTML = "倒计时结束";
  }
}

// 每秒更新一次倒计时
var countdownInterval = setInterval(updateCountdown, 1000);