// get current time for UTC timezone
const d = new Date();
const year = d.getUTCFullYear();
const month = d.getUTCMonth();
const day = d.getUTCDate();
// set time to begin day UTC
const startTime = Date.UTC(year, month, day, 0, 0, 0, 0);
//set time to end day UTC
const endTime = Date.UTC(year, month, day, 23, 59, 0, 0);

如果你对UTC时间的开始/结束感兴趣，你也可以使用模运算符:

const now = new Date().getTime();
let startOfDay = now - (now % 86400000);
let endDate = startOfDay + 86400000;

其中86400是一天的秒数，结果变量是Epoch(以毫秒为单位)。

如果你喜欢日期对象:

const now = new Date().getTime();
let startOfDay = new Date(now - (now % 86400000));
let endDate = new Date(now - (now % 86400000) + 86400000);

这可能有点棘手，但你可以使用Intl.DateTimeFormat。

下面的代码片段可以帮助您将任何时区的任何日期转换为开始/结束时间。

const beginingOfDay = (options = {}) => { const { date = new Date(), timeZone } = options; const parts = Intl.DateTimeFormat("en-US", { timeZone, hourCycle: "h23", hour: "numeric", minute: "numeric", second: "numeric", }).formatToParts(date); const hour = parseInt(parts.find((i) => i.type === "hour").value); const minute = parseInt(parts.find((i) => i.type === "minute").value); const second = parseInt(parts.find((i) => i.type === "second").value); return new Date( 1000 * Math.floor( (date - hour * 3600000 - minute * 60000 - second * 1000) / 1000 ) ); }; const endOfDay = (...args) => new Date(beginingOfDay(...args).getTime() + 86399999); const beginingOfYear = () => {}; console.log(beginingOfDay({ timeZone: "GMT" })); console.log(endOfDay({ timeZone: "GMT" })); console.log(beginingOfDay({ timeZone: "Asia/Tokyo" })); console.log(endOfDay({ timeZone: "Asia/Tokyo" }));

在MomentJs中，我们可以这样声明它:

   const start = moment().format('YYYY-MM-DD 00:00:01');
   const end = moment().format('YYYY-MM-DD 23:59:59');

供参考(合并后的Tvanfosson)

当你调用函数时，它将返回实际日期=>日期

export const today = {
  iso: {
    start: () => new Date(new Date().setHours(0, 0, 0, 0)).toISOString(),
    now: () => new Date().toISOString(),
    end: () => new Date(new Date().setHours(23, 59, 59, 999)).toISOString()
  },
  local: {
  start: () => new Date(new Date(new Date().setHours(0, 0, 0, 0)).toString().split('GMT')[0] + ' UTC').toISOString(),
  now: () => new Date(new Date().toString().split('GMT')[0] + ' UTC').toISOString(),
  end: () => new Date(new Date(new Date().setHours(23, 59, 59, 999)).toString().split('GMT')[0] + ' UTC').toISOString()
  }
}

//如何使用

today.local.now(); //"2018-09-07T01:48:48.000Z" BAKU +04:00
today.iso.now(); // "2018-09-06T21:49:00.304Z" * 

*适用于即时时间类型的Java8自动转换您的本地时间取决于您的地区。(如果你打算写全局应用程序)

如果您只对GMT的时间戳感兴趣，也可以这样做，它可以方便地适应不同的间隔(小时:1000 * 60 * 60,12小时:1000 * 60 * 60 * 12，等等)。

const interval = 1000 * 60 * 60 * 24; // 24 hours in milliseconds

let startOfDay = Math.floor(Date.now() / interval) * interval;
let endOfDay = startOfDay + interval - 1; // 23:59:59:9999