javascript - 下周开始计时数据

Question

function countDown(){
  // Set the date we're counting down to
  var countDownDate = new Date("july 11, 2017 10:19:00").getTime();

  // Update the count down every 1 second
  var x = setInterval(function() {

      // Get todays date and time
      var now = new Date().getTime();

      // Find the distance between now an 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);

      // Output the result in an element with id="demo"
      document.getElementById("demo").innerHTML = days + "d " + hours + "h "
      + minutes + "m " + seconds + "s ";

      // If the count down is over, write some text 
      if (distance < 0) {
          countDownDate = new Date("july 18, 2017 10:19:00").getTime();
      }
  }, 1000);

}

countDown();

我想要达到的是每周计时器都会开始计数到下周。 我每周都会在同一天同一时间开始一些事情。

我不想每周都重写代码:/

谢谢。

Answer 1

那么为什么仅仅为了计算距离下周开始还剩多少秒就需要如此多的计算呢？例如，我正在编写示例代码来计算它。

function distranceToNextWeekStartInSeconds() {
    var now = new Date()
    var dayDiff = 7 - now.getDay();
    var startOfNextWeek = new Date(now.valueOf());
    startOfNextWeek.setDate(now.getDate() + dayDiff);
    startOfNextWeek.setHours(0);
    startOfNextWeek.setMinutes(0);
    startOfNextWeek.setSeconds(0);
    return Math.floor((startOfNextWeek - now) / 1000);
}

console.log('Seconds remaining to next week start: ' + distranceToNextWeekStartInSeconds())

您可以简单地在计时器内调用此函数来进行实时计算和显示，就是这样。