在JavaScript中减去日期。

Does anybody know of an easy way of taking a date (e.g. Today) and going back X days?

有没有人知道一种简单的约会方式(比如今天)，然后回到X日?

So, for example, if I want to calculate the date 5 days before today.

举个例子，如果我想计算5天之前的日期。

25 个解决方案

#1

Try something like this:

试试这样:

 var d = new Date();
 d.setDate(d.getDate()-5);

Note that this modifies the date object and returns the time value of the updated date.

注意，这会修改日期对象并返回更新日期的时间值。

var d = new Date();

document.write('Today is: ' + d.toLocaleString());

d.setDate(d.getDate() - 5);

document.write('<br>5 days ago was: ' + d.toLocaleString());

#2

var dateOffset = (24*60*60*1000) * 5; //5 days
var myDate = new Date();
myDate.setTime(myDate.getTime() - dateOffset);

If you're performing lots of headachy date manipulation throughout your web application, DateJS will make your life much easier:

如果您在整个web应用程序中执行大量的headachy日期操作，DateJS将使您的生活更加轻松:

http://simonwillison.net/2007/Dec/3/datejs/

http://simonwillison.net/2007/Dec/3/datejs/

#3

It goes something like this:

它是这样的:

var d = new Date(); // today!
var x = 5; // go back 5 days!
d.setDate(d.getDate() - x);

#4

I noticed that the getDays+ X doesn't work over day/month boundaries. Using getTime works as long as your date is not before 1970.

我注意到getDays+ X不能超过一天/月的边界。使用getTime工作只要你的日期不在1970年之前。

var todayDate = new Date(), weekDate = new Date();
weekDate.setTime(todayDate.getTime()-(7*24*3600000));

#5

I made this prototype for Date so that I could pass negative values to subtract days and positive values to add days.

我做了这个原型，以便我可以通过负值来减去天数和正值来增加天数。

if(!Date.prototype.adjustDate){
    Date.prototype.adjustDate = function(days){
        var date;

        days = days || 0;

        if(days === 0){
            date = new Date( this.getTime() );
        } else if(days > 0) {
            date = new Date( this.getTime() );

            date.setDate(date.getDate() + days);
        } else {
            date = new Date(
                this.getFullYear(),
                this.getMonth(),
                this.getDate() - Math.abs(days),
                this.getHours(),
                this.getMinutes(),
                this.getSeconds(),
                this.getMilliseconds()
            );
        }

        this.setTime(date.getTime());

        return this;
    };
}

So, to use it i can simply write:

因此，我可以简单地写:

var date_subtract = new Date().adjustDate(-4),
    date_add = new Date().adjustDate(4);

#6

split your date into parts, then return a new Date with the adjusted values

将你的约会分成不同的部分，然后用调整后的值返回一个新的日期。

function DateAdd(date, type, amount){
    var y = date.getFullYear(),
        m = date.getMonth(),
        d = date.getDate();
    if(type === 'y'){
        y += amount;
    };
    if(type === 'm'){
        m += amount;
    };
    if(type === 'd'){
        d += amount;
    };
    return new Date(y, m, d);
}

Remember that the months are zero based, but the days are not. ie new Date(2009, 1, 1) == 01 February 2009, new Date(2009, 1, 0) == 31 January 2009;

记住，每个月都是零，但日子不是。2009年2月1日，2009年2月1日，2009年2月1日，2009年1月31日;

#7

get moment.js. All the cool kids use it. It has more formatting options, etc. Where

得到moment.js。所有的酷孩子都用它。它有更多的格式化选项，等等。

var n = 5;
var dateMnsFive = moment(<your date>).subtract(n , 'day');

Optional! Convert to JS Date obj for Angular binding.

可选!转换到JS日期obj的角度绑定。

var date = new Date(dateMnsFive.toISOString());

Optional! Format

可选!格式

var date = dateMnsFive.format("YYYY-MM-DD");

#8

I like doing the maths in milliseconds. So use Date.now()

我喜欢用毫秒计算。所以使用Date.now()

var newDate = Date.now() + -5*24*3600*1000; // date 5 days ago in milliseconds

and if you like it formatted

如果你喜欢它的格式。

new Date(newDate).toString(); // or .toUTCString or .toISOString ...

NOTE: Date.now() doesn't work in older browsers (eg IE8 I think). Polyfill here.

注意:日期。现在()在旧浏览器中不起作用(如IE8)。Polyfill这里。

UPDATE June 2015

@socketpair pointed out my sloppiness. As s/he says "Some day in year have 23 hours, and some 25 due to timezone rules".

@socketpair指出了我的马虎。正如s/他所说，“一年中的某一天有23个小时，而有25个小时是由于时区规则”。

To expand on that, the answer above will have daylightsaving inaccuracies in the case where you want to calculate the LOCAL day 5 days ago in a timezone with daylightsaving changes and you

若要扩展这一点，上面的答案将会在您想要计算的情况下，在您想要计算的地方，在5天前的一个时区里，您需要使用daylightsaving changes和您。

• assume (wrongly) that Date.now() gives you the current LOCAL now time, or
• 假设(错误地)那个日期。现在()给您当前本地时间，或。
• use .toString() which returns the local date and therefore is incompatible with the Date.now() base date in UTC.
• 使用. tostring()返回本地日期，因此与日期不兼容。

However, it works if you're doing your math all in UTC, eg

然而，如果你在UTC(例如)做你的数学，它就会起作用。

A. You want the UTC date 5 days ago from NOW (UTC)

A.您需要5天前的UTC时间(UTC)

var newDate = Date.now() + -5*24*3600*1000; // date 5 days ago in milliseconds UTC
new Date(newDate).toUTCString(); // or .toISOString(), BUT NOT toString

B. You start with a UTC base date other than "now", using Date.UTC()

B.你从一个UTC基本日期开始，而不是“现在”，使用日期。UTC()

newDate = new Date(Date.UTC(2015, 3, 1)).getTime() + -5*24*3600000;
new Date(newDate).toUTCString(); // or .toISOString BUT NOT toString

#9

A few of the existing solutions were close, but not quite exactly what I wanted. This function works with both positive or negative values and handles boundary cases.

现有的一些解决方案很接近，但并不完全符合我的要求。这个函数与正负值一起工作，处理边界情况。

function addDays(date, days) {
    return new Date(
        date.getFullYear(),
        date.getMonth(),
        date.getDate() + days,
        date.getHours(),
        date.getMinutes(),
        date.getSeconds(),
        date.getMilliseconds()
    );
}

#10

I find a problem with the getDate()/setDate() method is that it too easily turns everything into milliseconds, and the syntax is sometimes hard for me to follow.

我发现getDate()/setDate()方法的一个问题是，它太容易将所有东西转换成毫秒，而语法有时对我来说很难遵循。

Instead I like to work off the fact that 1 day = 86,400,000 milliseconds.

相反，我喜欢计算1天= 86,400,000毫秒的事实。

So, for your particular question:

所以，对于你的特殊问题:

today = new Date()
days = 86400000 //number of milliseconds in a day
fiveDaysAgo = new Date(today - (5*days))

Works like a charm.

就像一个魅力。

I use this method all the time for doing rolling 30/60/365 day calculations.

我一直用这个方法来做30/60/365天计算。

You can easily extrapolate this to create units of time for months, years, etc.

你可以很容易地推断出它能创造几个月、几年等等的时间单位。

#11

function addDays (date, daysToAdd) {
  var _24HoursInMilliseconds = 86400000;
  return new Date(date.getTime() + daysToAdd * _24HoursInMilliseconds);
};

var now = new Date();

var yesterday = addDays(now, - 1);

var tomorrow = addDays(now, 1);

#12

The top answers led to a bug in my code where on the first of the month it would set a future date in the current month. Here is what I did,

上面的答案导致了我的代码中出现了一个bug，在本月的第一个月，它将在本月设置一个未来的日期。这就是我所做的，

curDate = new Date(); // Took current date as an example
prvDate = new Date(0); // Date set to epoch 0
prvDate.setUTCMilliseconds((curDate - (5 * 24 * 60 * 60 * 1000))); //Set epoch time

#13

A easy way to manage dates is use Moment.js

管理日期的一种简单方法是使用Moment.js。

You can use add. Example

您可以使用add. Example。

var startdate = "20.03.2014";
var new_date = moment(startdate, "DD.MM.YYYY");
new_date.add(5, 'days'); //Add 5 days to start date
alert(new_date);

Docs http://momentjs.com/docs/#/manipulating/add/

文档http://momentjs.com/docs/ /操作/添加/

#14

for me all the combinations worked fine with below code snipplet , the snippet is for Angular-2 implementation , if you need to add days , pass positive numberofDays , if you need to substract pass negative numberofDays

对于我来说，所有的组合都可以很好地使用下面的代码snipplet，这段代码是用于Angular-2实现的，如果您需要添加天数，那么要传递正数的天数，如果您需要减去通过负数的天数。

function addSubstractDays(date: Date, numberofDays: number): Date {
let d = new Date(date);
return new Date(
    d.getFullYear(),
    d.getMonth(),
    (d.getDate() + numberofDays)
);
}

#15

I get good mileage out of date.js:

我能从约会中得到好处。

http://www.datejs.com/

http://www.datejs.com/

d = new Date();
d.add(-10).days();  // subtract 10 days

Nice!

好了!

Website includes this beauty:

网站包括这种美:

Datejs doesn’t just parse strings, it slices them cleanly in two

Datejs不只是解析字符串，它将它们整齐地分成两部分。

#16

When setting the date, the date converts to milliseconds, so you need to convert it back to a date:

设置日期时，日期转换为毫秒，因此您需要将其转换为日期:

This method also take into consideration, new year change etc.

这种方法也要考虑到，新年变化等。

function addDays( date, days ) {
    var dateInMs = date.setDate(date.getDate() - days);
    return new Date(dateInMs);
}

var date_from = new Date();
var date_to = addDays( new Date(), parseInt(days) );

#17

You can using Javascript.

您可以使用Javascript。

var CurrDate = new Date(); // Current Date
var numberOfDays = 5;
var days = CurrDate.setDate(CurrDate.getDate() + numberOfDays);
alert(days); // It will print 5 days before today

For PHP,

对于PHP,

$date =  date('Y-m-d', strtotime("-5 days")); // it shows 5 days before today.
echo $date;

Hope it will help you.

希望它能帮到你。

#18

var d = new Date();

document.write('Today is: ' + d.toLocaleString());

d.setDate(d.getDate() - 31);

document.write('<br>5 days ago was: ' + d.toLocaleString());

#19

I like the following because it is one line. Not perfect with DST changes but usually good enough for my needs.

我喜欢下面这一行，因为它是一行。虽然不完美，但通常足够满足我的需要。

var fiveDaysAgo = new Date(new Date() - (1000*60*60*24*5));

#20

var d = new Date();

document.write('Today is: ' + d.toLocaleString());

d.setDate(d.getDate() - 100);

document.write('<br>100 days ago was: ' + d.toLocaleString());

#21

without using the second variable, you can replace 7 for with your back x days

不使用第二个变量，可以用后x天替换7。

let d=new Date(new Date().getTime() - (7 * 24 * 60 * 60 * 1000))

让d=new Date(new Date().getTime() - (7 * 24 * 60 * 60 * 1000))

#22

I converted into millisecond and deducted days else month and year won't change and logical

我转换成毫秒，扣除天数，其他月份和年份不会变化和逻辑。

var numberOfDays = 10;//number of days need to deducted or added
var date = "01-01-2018"// date need to change
var dt = new Date(parseInt(date.substring(6), 10),        // Year
              parseInt(date.substring(3,5), 10) - 1, // Month (0-11)
              parseInt(date.substring(0,2), 10));
var new_dt = dt.setMilliseconds(dt.getMilliseconds() - numberOfDays*24*60*60*1000);
new_dt = new Date(new_dt);
var changed_date = new_dt.getDate()+"-"+(new_dt.getMonth()+1)+"-"+new_dt.getFullYear();

Hope helps

希望能帮助

#23

If you want to both subtract a number of days and format your date in a human readable format, you should consider creating a custom DateHelper object that looks something like this :

如果您想要同时减去若干天并以人类可读的格式格式化日期，那么您应该考虑创建一个自定义的DateHelper对象，它看起来如下:

var DateHelper = {
    addDays : function(aDate, numberOfDays) {
        aDate.setDate(aDate.getDate() + numberOfDays); // Add numberOfDays
        return aDate;                                  // Return the date
    },
    format : function format(date) {
        return [
           ("0" + date.getDate()).slice(-2),           // Get day and pad it with zeroes
           ("0" + (date.getMonth()+1)).slice(-2),      // Get month and pad it with zeroes
           date.getFullYear()                          // Get full year
        ].join('/');                                   // Glue the pieces together
    }
}

// With this helper, you can now just use one line of readable code to :
// ---------------------------------------------------------------------
// 1. Get the current date
// 2. Subtract 5 days
// 3. Format it
// 4. Output it
// ---------------------------------------------------------------------
document.body.innerHTML = DateHelper.format(DateHelper.addDays(new Date(), -5));

(see also this Fiddle)

(参见本小提琴)

#24

var daysToSubtract = 3;
$.datepicker.formatDate('yy/mm/dd', new Date() - daysToSubtract) ;

#25

var my date = new Date().toISOString().substring(0, 10);

it can give you only date like 2014-06-20. hope will help

它只能给你像2014-06-20那样的日期。希望能帮助