如何使用JavaScript将日期添加到当前日期?JavaScript是否有像.NET的AddDay()那样的内置函数?


当前回答

这些答案让我感到困惑,我更喜欢:

var ms = new Date().getTime() + 86400000;
var tomorrow = new Date(ms);

getTime()给出了自1970年以来的毫秒数,86400000是一天中的毫秒数。因此,ms包含所需日期的毫秒。

使用毫秒构造函数可以得到所需的日期对象。

其他回答

一些扩展Date的实现https://gist.github.com/netstart/c92e09730f3675ba8fb33be48520a86d

/**
 * just import, like
 *
 * import './../shared/utils/date.prototype.extendions.ts';
 */
declare global {
  interface Date {
    addDays(days: number, useThis?: boolean): Date;

    addSeconds(seconds: number): Date;

    addMinutes(minutes: number): Date;

    addHours(hours: number): Date;

    addMonths(months: number): Date;

    isToday(): boolean;

    clone(): Date;

    isAnotherMonth(date: Date): boolean;

    isWeekend(): boolean;

    isSameDate(date: Date): boolean;

    getStringDate(): string;
  }
}

Date.prototype.addDays = function(days: number): Date {
  if (!days) {
    return this;
  }
  this.setDate(this.getDate() + days);
  return this;
};

Date.prototype.addSeconds = function(seconds: number) {
  let value = this.valueOf();
  value += 1000 * seconds;
  return new Date(value);
};

Date.prototype.addMinutes = function(minutes: number) {
  let value = this.valueOf();
  value += 60000 * minutes;
  return new Date(value);
};

Date.prototype.addHours = function(hours: number) {
  let value = this.valueOf();
  value += 3600000 * hours;
  return new Date(value);
};

Date.prototype.addMonths = function(months: number) {
  const value = new Date(this.valueOf());

  let mo = this.getMonth();
  let yr = this.getYear();

  mo = (mo + months) % 12;
  if (0 > mo) {
    yr += (this.getMonth() + months - mo - 12) / 12;
    mo += 12;
  } else {
    yr += ((this.getMonth() + months - mo) / 12);
  }

  value.setMonth(mo);
  value.setFullYear(yr);
  return value;
};

Date.prototype.isToday = function(): boolean {
  const today = new Date();
  return this.isSameDate(today);
};

Date.prototype.clone = function(): Date {
  return new Date(+this);
};

Date.prototype.isAnotherMonth = function(date: Date): boolean {
  return date && this.getMonth() !== date.getMonth();
};

Date.prototype.isWeekend = function(): boolean {
  return this.getDay() === 0 || this.getDay() === 6;
};

Date.prototype.isSameDate = function(date: Date): boolean {
  return date && this.getFullYear() === date.getFullYear() && this.getMonth() === date.getMonth() && this.getDate() === date.getDate();
};

Date.prototype.getStringDate = function(): string {
  // Month names in Brazilian Portuguese
  const monthNames = ['Janeiro', 'Fevereiro', 'Março', 'Abril', 'Maio', 'Junho', 'Julho', 'Agosto', 'Setembro', 'Outubro', 'Novembro', 'Dezembro'];
  // Month names in English
  // let monthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
  const today = new Date();
  if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay()) {
    return 'Hoje';
    // return "Today";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() + 1) {
    return 'Amanhã';
    // return "Tomorrow";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() - 1) {
    return 'Ontem';
    // return "Yesterday";
  } else {
    return this.getDay() + ' de ' + this.monthNames[this.getMonth()] + ' de ' + this.getFullYear();
    // return this.monthNames[this.getMonth()] + ' ' + this.getDay() + ', ' +  this.getFullYear();
  }
};


export {};
var today = new Date();
var tomorrow = new Date();
tomorrow.setDate(today.getDate()+1);

小心,因为这可能很棘手。当设置明天时,它仅在当前值与今天的年份和月份匹配时有效。然而,通常将日期设置为“32”这样的数字仍然可以很好地将其移动到下一个月。

我实现的最简单的方法是使用Date()本身。`

const days = 15; 
// Date.now() gives the epoch date value (in milliseconds) of current date 
nextDate = new Date( Date.now() + days * 24 * 60 * 60 * 1000)

`

有一个setDate和一个getDate方法,允许您执行以下操作:

var newDate = aDate.setDate(aDate.getDate() + numberOfDays);

如果您想减去天数并将日期格式化为可读格式,则应考虑创建一个自定义DateHelper对象,其外观如下:

var日期助手={addDays:函数(aDate,numberOfDays){aDate.setDate(aDate.getDate()+天数);//添加天数return aDate;//返回日期},格式:函数格式(日期){返回[(“0”+date.getDate()).slice(-2),//获取日期并用零填充(“0”+(date.getMonth()+1)).slice(-2),//获取月份并用零填充date.getFullYear()//获取全年].ejoin('/');//把碎片粘在一起}}//有了这个助手,您现在只需使用一行可读代码即可:// ---------------------------------------------------------------------// 1. 获取当前日期// 2. 增加20天// 3. 格式化它// 4. 输出它// ---------------------------------------------------------------------document.body.innerHTML=DateHelper.format(DateHelper.addDays(new Date(),20));

(另见本Fiddle)

我对所提出的解决方案的夏令时有问题。

通过改用getUTCDate/setUTCDate,我解决了问题。

// Curried, so that I can create helper functions like `add1Day`
const addDays = num => date => {
  // Make a working copy so we don't mutate the supplied date.
  const d = new Date(date);

  d.setUTCDate(d.getUTCDate() + num);

  return d;
}