Subtract days from a date in JavaScript

Answer 1

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.

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

Answer 2

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.

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

So, for your particular question:

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

Works like a charm.

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

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

Answer 3

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

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

Answer 4

I get good mileage out of date.js:

http://www.datejs.com/

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

Nice!

Website includes this beauty:

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

Answer 5

A easy way to manage dates is use Moment.js

You can use 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/

Answer 6

If you want it all on one line instead.

5 days from today

//past
var thirtyDaysAgo = new Date(new Date().setDate(new Date().getDate() - 5));
//future
var thirtyDaysInTheFuture = new Date(new Date().setDate(new Date().getDate() + 5));

5 days from a specific date

 var pastDate = new Date('2019-12-12T00:00:00');

 //past
 var thirtyDaysAgo = new Date(new Date().setDate(pastDate.getDate() - 5));
 //future
 var thirtyDaysInTheFuture = new Date(new Date().setDate(pastDate.getDate() + 5));

I wrote a function you can use.

function AddOrSubractDays(startingDate, number, add) {
  if (add) {
    return new Date(new Date().setDate(startingDate.getDate() + number));
  } else {
    return new Date(new Date().setDate(startingDate.getDate() - number));
  }
}

console.log('Today : ' + new Date());
console.log('Future : ' + AddOrSubractDays(new Date(), 5, true));
console.log('Past : ' + AddOrSubractDays(new Date(), 5, false));