我需要最快的方法得到一周的第一天。例如:今天是11月11日,是星期四;我想要这周的第一天,也就是11月8日,一个星期一。我需要MongoDB映射函数的最快方法,有什么想法吗?


当前回答

我用这个:

let current_date = new Date();
let days_to_monday = 1 - current_date.getDay();
monday_date = current_date.addDays(days_to_monday);

// https://stackoverflow.com/a/563442/6533037
Date.prototype.addDays = function(days) {
    var date = new Date(this.valueOf());
    date.setDate(date.getDate() + days);
    return date;
}

它工作得很好。

其他回答

一个只有数学计算的例子,没有任何Date函数。

const date = new date (); Const ts = +日期; const mondayTS = ts % (60 * 60 * 24 * (7-4) * 1000); const monday =新的日期(星期一); console.log(monday.toISOString(), 'Day:', monday.getDay());

const formatTS = v => new Date(v).toISOString(); const adjust = (v, d = 1) => v - v % (d * 1000); const d = new Date('2020-04-22T21:48:17.468Z'); const ts = +d; // 1587592097468 const test = v => console.log(formatTS(adjust(ts, v))); test(); // 2020-04-22T21:48:17.000Z test(60); // 2020-04-22T21:48:00.000Z test(60 * 60); // 2020-04-22T21:00:00.000Z test(60 * 60 * 24); // 2020-04-22T00:00:00.000Z test(60 * 60 * 24 * (7-4)); // 2020-04-20T00:00:00.000Z, monday // So, what does `(7-4)` mean? // 7 - days number in the week // 4 - shifting for the weekday number of the first second of the 1970 year, the first time stamp second. // new Date(0) ---> 1970-01-01T00:00:00.000Z // new Date(0).getDay() ---> 4

周一上午00点到周一上午00点返回。

const now = new Date()
const startOfWeek = new Date(now.getFullYear(), now.getMonth(), now.getDate() - now.getDay() + 1)
const endOfWeek = new Date(now.getFullYear(), now.getMonth(), startOfWeek.getDate() + 7)

查看Date.js

Date.today().previous().monday()

扩展回答来自@Christian C. Salvadó和来自@Ayyash(对象是可变的)和@Awi和@Louis Ameline(设置时间为00:00:00)的信息

函数可以是这样的

function getMonday(d) {
  var day = d.getDay(),
      diff = d.getDate() - day + (day == 0 ? -6:1); // adjust when day is sunday
  d.setDate(diff);
  d.setHours(0,0,0,0); // set hours to 00:00:00

  return d; // object is mutable no need to recreate object
}

getMonday(new Date())

我用这个:

let current_date = new Date();
let days_to_monday = 1 - current_date.getDay();
monday_date = current_date.addDays(days_to_monday);

// https://stackoverflow.com/a/563442/6533037
Date.prototype.addDays = function(days) {
    var date = new Date(this.valueOf());
    date.setDate(date.getDate() + days);
    return date;
}

它工作得很好。