How to get "the day before a date" in javascript?

Question

These two stack overflow questions ask a similar question, but their solution doesn't seem to work for me: Javascript Yesterday Javascript code for showing yesterday's date and todays date

Given a date, I need the date of the prior day (the day before). Here's a fiddle with the solution suggested above, and a scenario that doesn't work for me: http://jsfiddle.net/s3dHV/

var date = new Date('04/28/2013 00:00:00');
var yesterday = new Date();
yesterday.setDate(date.getDate() - 1);
alert('If today is ' + date + ' then yesterday is ' + yesterday);

For me, that alerts

If today is Sun Apr 28 2013 00:00:00 GMT-0400 (Eastern Daylight Time) then yesterday is Monday May 27 2013 11:12:06 GMT-0400 (Eastern Daylight Time).

Which is obviously incorrect. Why?

Reverse this question: stackoverflow.com/questions/4868241/javascript-date-1 — David Starkey
– David Starkey, Commented May 6, 2013 at 15:17
The solution posted in that thread is exactly the same as the ones I've linked to... — Arbiter
– Arbiter, Commented May 6, 2013 at 15:35
Read comments: date.setTime(date.getTime() + 86400000); - venkatagiri — David Starkey
– David Starkey, Commented May 6, 2013 at 15:36

Pointy · Accepted Answer · 2013-05-06 15:17:21Z

63

You're making a whole new date.

var yesterday = new Date(date.getTime());
yesterday.setDate(date.getDate() - 1);

That'll make you a copy of the first date. When you call setDate(), it just affects the day-of-the-month, not the whole thing. If you start with a copy of the original date, and then set the day of the month back, you'll get the right answer.

answered May 6, 2013 at 15:17

Pointy

415k62 gold badges600 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Robert Harvey Over a year ago

That's pretty goofy, if you ask me. They should have called it setDay(), not setDate().

T.J. Crowder Over a year ago

@RobertHarvey: The sheer volume of things they should have done differently with the JavaScript Date object would (and probably does) fill volumes...

Pointy Over a year ago

@RobertHarvey yes, or setDayOfMonth or whatever. I have a soft spot however because the Date object (while having all sorts of problems) is really handy.

T.J. Crowder Over a year ago

But being fair: One of the right things is that Pointy's code works even if date is the first day of a month, and so date.getDate() - 1 is 0. It will give you Feb 28th (or Feb 29th as appropriate) if date is March 1st, for instance.

Pointy Over a year ago

@T.J.Crowder yes exactly - it makes doing things like building calendar displays really easy.

Vadim · Accepted Answer · 2013-05-06 15:19:19Z

17

Try this:

var date = new Date('04/28/2013 00:00:00');
var yesterday = new Date(date.getTime() - 24*60*60*1000);

answered May 6, 2013 at 15:19

Vadim

8,7744 gold badges47 silver badges52 bronze badges

2 Comments

Arbiter Over a year ago

Not all days are 24 hours long. We have daylight savings time in my country which means we have a 23 hour day once a year, and a 25 hour day once a year. Your code won't handle this correctly.

izogfif Over a year ago

@Arbiter: don't forget about leap seconds!

Mouad Chaouki · Accepted Answer · 2022-03-03 13:09:34Z

0

Use this simple function :

private _getYesterdayDate(): Date{
  const yesterday:Date = new Date();
  yesterday.setDate(yesterday.getDate() - 1);
  return yesterday;
}

The function works even if date is the first day of a month, and you used date.getDate() - 1, it will give you last day in the previous month as appropriate

edited Mar 3, 2022 at 13:09

answered Mar 3, 2022 at 13:02

Mouad Chaouki

5785 silver badges7 bronze badges

Comments

markus · Accepted Answer · 2018-10-19 16:44:44Z

-4

var allmonths = [
    '01', '02', '03', '04', '05', '06', '07', '08', '09', '10', '11', '12'
];
var alldates = [
    '01', '02', '03', '04', '05', '06', '07', '08', '09', '10',
    '11', '12', '13', '14', '15', '16', '17', '18', '19', '20',
    '21', '22', '23', '24', '25', '26', '27', '28', '29', '30', '31'
];

var today = "2014-12-25";   
var aDayBefore = new Date(today);
aDayBefore.setDate(aDayBefore.getDate() - 1);

document.write(aDayBefore.getFullYear() 
  + '-' + allmonths[aDayBefore.getMonth()] 
  + '-' + alldates[aDayBefore.getDate() - 1]);

edited Oct 19, 2018 at 16:44

markus

40.8k23 gold badges100 silver badges143 bronze badges

answered Dec 3, 2014 at 6:22

Riyanto Wibowo

3641 gold badge6 silver badges13 bronze badges

1 Comment

Blue Over a year ago

Thank you for this code snippet, which might provide some limited, immediate help. A proper explanation would greatly improve its long-term value by showing why this is a good solution to the problem, and would make it more useful to future readers with other, similar questions. Please edit your answer to add some explanation, including the assumptions you've made.

Collectives™ on Stack Overflow

How to get "the day before a date" in javascript?

4 Answers 4

5 Comments

2 Comments

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

5 Comments

2 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related