使用 JavaScript 将工作日添加到日期

Question

如何使用 JavaScript 添加工作日（即周一至周五）在必要时自动添加周末？

因此，如果我要在今天（2016 年 11 月 22 日星期二）加上 5 个工作日，结果应该是“2016 年 11 月 29 日星期二”而不是“2016 年 11 月 27 日星期日”。

Answer 1

可以使用Date 的setDate 函数（结合getDate）在日期上添加天数，即-

var myDate = new Date(); // Tue 22/11/2016
myDate.setDate(myDate.getDate() + 3); // Fri 25/11/2016

因此，一旦您计算出工作日期间的周末天数，您就可以将其和所需的工作日数添加到开始日期以获得最终日期。

这个功能应该可以工作，但显然这不会考虑到国定假日 -

function addWorkDays(startDate, days) {
    if(isNaN(days)) {
        console.log("Value provided for \"days\" was not a number");
        return
    }
    if(!(startDate instanceof Date)) {
        console.log("Value provided for \"startDate\" was not a Date object");
        return
    }
    // Get the day of the week as a number (0 = Sunday, 1 = Monday, .... 6 = Saturday)
    var dow = startDate.getDay();
    var daysToAdd = parseInt(days);
    // If the current day is Sunday add one day
    if (dow == 0)
        daysToAdd++;
    // If the start date plus the additional days falls on or after the closest Saturday calculate weekends
    if (dow + daysToAdd >= 6) {
        //Subtract days in current working week from work days
        var remainingWorkDays = daysToAdd - (5 - dow);
        //Add current working week's weekend
        daysToAdd += 2;
        if (remainingWorkDays > 5) {
            //Add two days for each working week by calculating how many weeks are included
            daysToAdd += 2 * Math.floor(remainingWorkDays / 5);
            //Exclude final weekend if remainingWorkDays resolves to an exact number of weeks
            if (remainingWorkDays % 5 == 0)
                daysToAdd -= 2;
        }
    }
    startDate.setDate(startDate.getDate() + daysToAdd);
    return startDate;
}

//And use it like so (months are zero based)
var today = new Date(2016, 10, 22);
today = addWorkDays(today, 5); // Tue Nov 29 2016 00:00:00 GMT+0000 (GMT Standard Time)

它也可以添加到Date原型中-

Date.prototype.addWorkDays = function (days) {
    if(isNaN(days)) {
        console.log("Value provided for \"days\" was not a number");
        return
    }

    // Get the day of the week as a number (0 = Sunday, 1 = Monday, .... 6 = Saturday)
    var dow = this.getDay();
    var daysToAdd = parseInt(days);
    // If the current day is Sunday add one day
    if (dow == 0) {
        daysToAdd++;
    }
    // If the start date plus the additional days falls on or after the closest Saturday calculate weekends
    if (dow + daysToAdd >= 6) {
        //Subtract days in current working week from work days
        var remainingWorkDays = daysToAdd - (5 - dow);
        //Add current working week's weekend
        daysToAdd += 2;
        if (remainingWorkDays > 5) {
            //Add two days for each working week by calculating how many weeks are included
            daysToAdd += 2 * Math.floor(remainingWorkDays / 5);
            //Exclude final weekend if the remainingWorkDays resolves to an exact number of weeks
            if (remainingWorkDays % 5 == 0)
                daysToAdd -= 2;
        }
    }
    this.setDate(this.getDate() + daysToAdd);
};

//And use it like so (months are zero based)
var today = new Date(2016, 10, 22)
today.addWorkDays(5); // Tue Nov 29 2016 00:00:00 GMT+0000 (GMT Standard Time)

Answer 2

我认为你可以使用moment-business-days。

例子：

// 22-11-2016 is Tuesday, DD-MM-YYYY is the format 
moment('22-11-2016', 'DD-MM-YYYY').businessAdd(5)._d // Tue Nov 29 2016 00:00:00 GMT-0600 (CST) 

Answer 3

如果是添加几天，而不是几千天，那么这更容易且更具可读性：

const currentDate = new Date('2021-11-18');
console.log(currentDate.toString()); // "Thu Nov 18 2021 00:00:00 GMT+0000"

const numToAdd = 5;

for (let i = 1; i <= numToAdd; i++) {
  currentDate.setDate(currentDate.getDate() + 1);
  if (currentDate.getDay() === 6) {
    currentDate.setDate(currentDate.getDate() + 2);
  }
  else if (currentDate.getDay() === 0) {
    currentDate.setDate(currentDate.getDate() + 1);
  }
}

console.log(currentDate.toString()); // "Thu Nov 25 2021 00:00:00 GMT+0000"

Answer 4

const date = new Date('2000-02-02')
const daysToAdd = mapToWorkdays(date, 37)

date.setUTCDate(date.getUTCDate() + daysToAdd)

console.log( date.toISOString().split('T')[0] )
// prints 2000-03-24

/**
 * @param {Date} date starting date
 * @param {number} add number of workdays to add
 * @return {number} total number of days to add to reach correct date
 */
function mapToWorkdays(date, add) {
  const wd = weekday(date)
  
  let r = Math.trunc(add / 5) * 2
  const rem = add % 5

  if (wd > 4) r += (6-wd)
  else if (wd+rem > 4) r += 2

  return add + r
}

/**
 * @param {Date} date
 * @return {number} day of the week in range of 0..6 (monday..sunday)
 */
function weekday(date) { return (date.getUTCDay()+ 6) % 7 }

Answer 5

更新了上面的脚本，如果给出负数，也会减去工作日...

function addWorkDays(startDate, days) {
    var isAddingDays = (days > 0);
    var isDaysToAddMoreThanWeek = (days > 5 || days < -5);

    if (isNaN(days)) {
        console.log("Value provided for \"days\" was not a number");
        return
    }
    if (!(startDate instanceof Date)) {
        console.log("Value provided for \"startDate\" was not a Date object");
        return
    }
    var dow = startDate.getDay();
    var daysToAdd = parseInt(days);

    if ((dow === 0 && isAddingDays) || (dow === 6 && !isAddingDays)) {
        daysToAdd = daysToAdd + (1 * (isAddingDays ? 1 : -1));
    } else if ((dow === 6 && isAddingDays) || (dow === 0 && !isAddingDays)) {
        daysToAdd = daysToAdd + (2 * (isAddingDays ? 1 : -1));
    }

    if (isDaysToAddMoreThanWeek) {
        daysToAdd = daysToAdd + (2 * (Math.floor(days / 5)));

        if (days % 5 != 0)
            daysToAdd = daysToAdd + (2 * (isAddingDays ?  -1 : 1));
    }

    startDate.setDate(startDate.getDate() + daysToAdd);
    var newDate = moment(startDate).format('MM/DD/YYYY');
    return newDate;
}