momentjs 日期差返回错误

Question

我使用countdown.js 并想将60 days 添加到date（数据取自数据库）。我在targetDay 中执行此操作，它工作正常，现在我想从现在开始计算这个日期，但它返回一个奇怪的日期"1969-11-05T21:24:07.416Z" 为什么？

const nowDate = moment();
const targetDay = moment('2020-10-24 14:25:26').add('60', 'days');
const countdown = moment(nowDate - targetDay);


console.log(countdown);
//const diff = targetDay.fromNow();

const count_days = countdown.format('D');
const count_hours = countdown.format('HH');
const count_minutes = countdown.format('mm');
const count_seconds = countdown.format('ss');
console.log(count_days + ' days:' + count_hours + ' hrs:' + count_minutes + ' m:' + count_seconds + ' s');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>

我尝试了fromNow() 函数，但它返回string。我想做的是，从现在开始对目标日期进行倒计时。

Answer 1

您可以使用.duration()，然后使用.hours() 和.minutes() 和.seconds() 获取剩余时间，这些函数从milliseconds 转换而来

https://momentjs.com/docs/#/durations/

setInterval(function() { // remove
  const nowDate = moment();
  const targetDay = moment('2030-10-24 14:25:26').add('60', 'days'); // I changed to 2030 to keep this snippet live for future ;)
  const countdown = moment.duration(targetDay.diff(nowDate));

  const count_days = Math.floor(countdown.asDays());
  const count_hours = countdown.hours();
  const count_minutes = countdown.minutes();
  const count_seconds = countdown.seconds();
  $('div').text(count_days + ' days:' + count_hours + ' hrs:' + count_minutes + ' m:' + count_seconds + ' s');
}, 1000); // remove

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>
<div></div>

只需在您的代码中删除setInterval，这只是为了演示！

---

我改为 2030 年是为了让这个 sn-p 在未来继续存在；）

Answer 2

使用moment.diff() 代替方向数学减法。

这将创建一个moment.duration（默认以毫秒为单位）。

const nowDate = moment();
const targetDay = moment('2020-10-24 14:25:26').add('60', 'days');
const countdownDiff = targetDay.diff(nowDate)
// 4855463420

您的差异常数也应该以持续时间来衡量，因为附加差异的格式不是持续时间。

例如。 10 月 28 日 + 60 天 => 12 月 28 日。但是moment('28-12-2020').format('D') 是28 而不是您要显示的60。

因此，您还需要将它们单独存储为差异

const count_days = targetDay.diff(nowDate, 'd');
const count_hours = targetDay.diff(nowDate, 'h');
const count_minutes = targetDay.diff(nowDate, 'm');
const count_seconds = targetDay.diff(nowDate, 's');

如果您希望将其转换回片刻，您可以将差异添加到原始片刻。这仅作为如何计算差异的说明

const countdown = nowDate.add(countdownDiff, 'ms')
// obviously this is redundant as it's the same as targetDay

这是一个工作示例：

const nowDate = moment();
const targetDay = moment('2020-10-24 14:25:26').add('60', 'days');
const countdownDiff = targetDay.diff(nowDate)
// 4855463420


const countdown = moment(nowDate).add(countdownDiff, 'ms')
// obviously this is redundant as it's the same as targetDay

const count_days = targetDay.diff(nowDate, 'days');
const count_hours = targetDay.diff(nowDate, 'h');
const count_minutes = targetDay.diff(nowDate, 'm');
const count_seconds = targetDay.diff(nowDate, 's');

console.log('Current day:', nowDate.format('Do MMM YYYY HH:mm'));
console.log('Target day:', targetDay.format('Do MMM YYYY HH:mm'));
console.log('Countdown end date', countdown.format('Do MMM YYYY HH:mm'));

console.log(count_days + ' days:' + count_hours + ' hrs:' + count_minutes + ' m:' + count_seconds + ' s');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>