Develop Reference

New Date () converting passed in yyyy-mm-dd to correct date minus one day [duplicate]

In my Java Script app I have the date stored in a format like so:
2011-09-24
Now when I try using the above value to create a new Date object (so I can retrieve the date in a different format), the date always comes back one day off. See below:
var date = new Date("2011-09-24");
console.log(date);
logs:
Fri Sep 23 2011 20:00:00 GMT-0400 (Eastern Daylight Time)

There are several crazy things that happen with a JS DATE object that convert strings, for example consider the following date you provided
Note: The following examples may or may not be ONE DAY OFF depending on YOUR timezone and current time.
new Date("2011-09-24"); // Year-Month-Day
// => Fri Sep 23 2011 17:00:00 GMT-0700 (MST) - ONE DAY OFF.
However, if we rearrange the string format to Month-Day-Year...
new Date("09-24-2011");
// => Sat Sep 24 2011 00:00:00 GMT-0700 (MST) - CORRECT DATE.
Another strange one
new Date("2011-09-24");
// => Fri Sep 23 2011 17:00:00 GMT-0700 (MST) - ONE DAY OFF AS BEFORE.
new Date("2011/09/24"); // change from "-" to "/".
// => Sat Sep 24 2011 00:00:00 GMT-0700 (MST) - CORRECT DATE.
We could easily change hyphens in your date "2011-09-24" when making a new date
new Date("2011-09-24".replace(/-/g, '\/')); // => "2011/09/24".
// => Sat Sep 24 2011 00:00:00 GMT-0700 (MST) - CORRECT DATE.
What if we had a date string like "2011-09-24T00:00:00"
new Date("2011-09-24T00:00:00");
// => Fri Sep 23 2011 17:00:00 GMT-0700 (MST) - ONE DAY OFF.
Now change hyphen to forward slash as before; what happens?
new Date("2011/09/24T00:00:00");
// => Invalid Date.
I typically have to manage the date format 2011-09-24T00:00:00 so this is what I do.
new Date("2011-09-24T00:00:00".replace(/-/g, '\/').replace(/T.+/, ''));
// => Sat Sep 24 2011 00:00:00 GMT-0700 (MST) - CORRECT DATE.
UPDATE
If you provide separate arguments to the Date constructor you can get other useful outputs as described below
Note: arguments can be of type Number or String. I'll show examples with mixed values.
Get the first month and day of a given year
new Date(2011, 0); // Normal behavior as months in this case are zero based.
// => Sat Jan 01 2011 00:00:00 GMT-0700 (MST)
Get the last month and day of a year
new Date((2011 + 1), 0, 0); // The second zero roles back one day into the previous month's last day.
// => Sat Dec 31 2011 00:00:00 GMT-0700 (MST)
Example of Number, String arguments. Note the month is March because zero based months again.
new Date(2011, "02");
// => Tue Mar 01 2011 00:00:00 GMT-0700 (MST)
If we do the same thing but with a day of zero, we get something different.
new Date(2011, "02", 0); // Again the zero roles back from March to the last day of February.
// => Mon Feb 28 2011 00:00:00 GMT-0700 (MST)
Adding a day of zero to any year and month argument will get the last day of the previous month. If you continue with negative numbers you can continue rolling back another day
new Date(2011, "02", -1);
// => Sun Feb 27 2011 00:00:00 GMT-0700 (MST)

Notice that Eastern Daylight Time is -4 hours and that the hours on the date you're getting back are 20.
20h + 4h = 24h
which is midnight of 2011-09-24. The date was parsed in UTC (GMT) because you provided a date-only string without any time zone indicator. If you had given a date/time string w/o an indicator instead (new Date("2011-09-24T00:00:00")), it would have been parsed in your local timezone. (Historically there have been inconsistencies there, not least because the spec changed more than once, but modern browsers should be okay; or you can always include a timezone indicator.)
You're getting the right date, you just never specified the correct time zone.
If you need to access the date values, you can use getUTCDate() or any of the other getUTC*() functions:
var d,
days;
d = new Date('2011-09-24');
days = ['Sun', 'Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'];
console.log(days[d.getUTCDay()]);

To normalize the date and eliminate the unwanted offset (tested here : https://jsfiddle.net/7xp1xL5m/ ):
var doo = new Date("2011-09-24");
console.log( new Date( doo.getTime() + Math.abs(doo.getTimezoneOffset()*60000) ) );
// Output: Sat Sep 24 2011 00:00:00 GMT-0400 (Eastern Daylight Time)
This also accomplishes the same and credit to #tpartee (tested here : https://jsfiddle.net/7xp1xL5m/1/ ):
var doo = new Date("2011-09-24");
console.log( new Date( doo.getTime() - doo.getTimezoneOffset() * -60000 ) );

I believe that it has to do with time-zone adjustment. The date you've created is in GMT and the default time is midnight, but your timezone is EDT, so it subtracts 4 hours. Try this to verify:
var doo = new Date("2011-09-25 EDT");

Just want to add that apparently adding a space at the end of the string will use UTC for creation.
new Date("2016-07-06")
> Tue Jul 05 2016 17:00:00 GMT-0700 (Pacific Daylight Time)
new Date("2016-07-06 ")
> Wed Jul 06 2016 00:00:00 GMT-0700 (Pacific Daylight Time)
Edit: This is not a recommended solution, just an alternative answer. Please do not use this approach since it is very unclear what is happening. There are a number of ways someone could refactor this accidentally causing a bug.

If you want to get hour 0 of some date in the local time zone, pass the individual date parts to the Date constructor.
new Date(2011,08,24); // month value is 0 based, others are 1 based.

if you need a simple solution for this see:
new Date('1993-01-20'.split('-'));

Your issue is specifically with time zone. Note part GMT-0400 - that is you're 4 hours behind GMT. If you add 4 hours to the displayed date/time, you'll get exactly midnight 2011/09/24. Use toUTCString() method instead to get GMT string:
var doo = new Date("2011-09-24");
console.log(doo.toUTCString());

This probably is not a good answer, but i just want to share my experience with this issue.
My app is globally use utc date with the format 'YYYY-MM-DD', while the datepicker plugin i use only accept js date, it's hard for me to consider both utc and js. So when i want to pass a 'YYYY-MM-DD' formatted date to my datepicker, i first convert it to 'MM/DD/YYYY' format using moment.js or whatever you like, and the date shows on datepicker is now correct. For your example
var d = new Date('2011-09-24'); // d will be 'Fri Sep 23 2011 20:00:00 GMT-0400 (EDT)' for my lacale
var d1 = new Date('09/24/2011'); // d1 will be 'Sat Sep 24 2011 00:00:00 GMT-0400 (EDT)' for my lacale
Apparently d1 is what i want. Hope this would be helpful for some people.

You can convert this date to UTC date by
new Date(Date.UTC(Year, Month, Day, Hour, Minute, Second))
And it is always recommended to use UTC (universal time zone) date instead of Date with local time, as by default dates are stored in Database with UTC. So, it is good practice to use and interpret dates in UTC format throughout entire project.
For example,
Date.getUTCYear(), getUTCMonth(), getUTCDay(), getUTCHours()
So, using UTC dates solves all the problem related to timezone issues.

This through me for a loop, +1 on zzzBov's answer. Here is a full conversion of a date that worked for me using the UTC methods:
//myMeeting.MeetingDate = '2015-01-30T00:00:00'
var myDate = new Date(myMeeting.MeetingDate);
//convert to JavaScript date format
//returns date of 'Thu Jan 29 2015 19:00:00 GMT-0500 (Eastern Standard Time)' <-- One Day Off!
myDate = new Date(myDate.getUTCFullYear(), myDate.getUTCMonth(), myDate.getUTCDate());
//returns date of 'Fri Jan 30 2015 00:00:00 GMT-0500 (Eastern Standard Time)' <-- Correct Date!

It means 2011-09-24 00:00:00 GMT, and since you're at GMT -4, it will be 20:00 the previous day.
Personally, I get 2011-09-24 02:00:00, because I'm living at GMT +2.

Though in the OP's case the timezone is EDT, there's not guarantee the user executing your script will be int he EDT timezone, so hardcoding the offset won't necessarily work. The solution I found splits the date string and uses the separate values in the Date constructor.
var dateString = "2011-09-24";
var dateParts = dateString.split("-");
var date = new Date(dateParts[0], dateParts[1] - 1, dateParts[2]);
Note that you have to account for another piece of JS weirdness: the month is zero-based.

I encountered this exact problem where my client was on Atlantic Standard Time. The date value the client retrieved was "2018-11-23" and when the code passed it into new Date("2018-11-23") the output for the client was for the previous day. I created a utility function as shown in the snippet that normalized the date, giving the client the expected date.
date.setMinutes(date.getMinutes() + date.getTimezoneOffset());
var normalizeDate = function(date) {
date.setMinutes(date.getMinutes() + date.getTimezoneOffset());
return date;
};
var date = new Date("2018-11-23");
document.getElementById("default").textContent = date;
document.getElementById("normalized").textContent = normalizeDate(date);
<h2>Calling new Date("2018-11-23")</h2>
<div>
<label><b>Default</b> : </label>
<span id="default"></span>
</div>
<hr>
<div>
<label><b>Normalized</b> : </label>
<span id="normalized"></span>
</div>

My solution to parse an ISO date without beeing annoyed by the timezone is to add a "T12:00:00" at the end before parsing it, because when it's noon at Greenwich, well the whole world is on the same day :
function toDate(isoDateString) {
// isoDateString is a string like "yyyy-MM-dd"
return new Date(`${isoDateString}T12:00:00`);
}
Before:
> new Date("2020-10-06")
> Date Mon Oct 05 2020 14:00:00 GMT-1000 (heure normale d’Hawaii - Aléoutiennes)
After:
> toDate("2020-10-06")
> Date Tue Oct 06 2020 12:00:00 GMT-1000 (heure normale d’Hawaii - Aléoutiennes)

if you're just looking to make sure the individual parts of the date stay the same for display purposes, *this appears to work, even when I change my timezone:
var doo = new Date("2011-09-24 00:00:00")
just add the zeros in there.
In my code I do this:
let dateForDisplayToUser =
new Date( `${YYYYMMDDdateStringSeparatedByHyphensFromAPI} 00:00:00` )
.toLocaleDateString(
'en-GB',
{ day: 'numeric', month: 'short', year: 'numeric' }
)
And I switch around my timezone on my computer and the date stays the same as the yyyy-mm-dd date string I get from the API.
But am I missing something/is this a bad idea ?
*at least in chrome. This Doesn't work in Safari ! as of this writing

As most answers are hacky, allow me to propose my very simple hack that worked for me: Set the script's timezone to UTC
process.env.TZ = 'UTC' // this has to be run before any use of dates
With this change, any timezone modifications are neutralized, so as long as you don't need the runner's actual timezone, this is probably the easiest fix.

// When the time zone offset is absent, date-only formats such as '2011-09-24'
// are interpreted as UTC time, however the date object will display the date
// relative to your machine's local time zone, thus producing a one-day-off output.
const date = new Date('2011-09-24');
console.log(date); // Fri Sep 23 2011 17:00:00 GMT-0700 (PDT)
console.log(date.toLocaleDateString('en-US')); // "9/23/2011"
// To ensure the date object displays consistently with your input, simply set
// the timeZone parameter to 'UTC' in your options argument.
console.log(date.toLocaleDateString('en-US', { timeZone: 'UTC' })); // "9/24/2011"

The best way to handle this without using more conversion methods,
var mydate='2016,3,3';
var utcDate = Date.parse(mydate);
console.log(" You're getting back are 20. 20h + 4h = 24h :: "+utcDate);
Now just add GMT in your date or you can append it.
var mydateNew='2016,3,3'+ 'GMT';
var utcDateNew = Date.parse(mydateNew);
console.log("the right time that you want:"+utcDateNew)
Live: https://jsfiddle.net/gajender/2kop9vrk/1/

I faced some issue like this. But my issue was the off set while getting date from database.
this is stroed in the database and it is in the UTC format.
2019-03-29 19:00:00.0000000 +00:00
So when i get from database and check date it is adding offset with it and send back to javascript.
It is adding +05:00 because this is my server timezone. My client is on different time zone +07:00.
2019-03-28T19:00:00+05:00 // this is what i get in javascript.
So here is my solution what i do with this issue.
var dates = price.deliveryDate.split(/-|T|:/);
var expDate = new Date(dates[0], dates[1] - 1, dates[2], dates[3], dates[4]);
var expirationDate = new Date(expDate);
So when date come from the server and have server offset so i split date and remove server offset and then convert to date. It resolves my issue.

Trying to add my 2 cents to this thread (elaborating on #paul-wintz answer).
Seems to me that when Date constructor receives a string that matches first part of ISO 8601 format (date part) it does a precise date conversion in UTC time zone with 0 time. When that date is converted to local time a date shift may occur
if midnight UTC is an earlier date in local time zone.
new Date('2020-05-07')
Wed May 06 2020 20:00:00 GMT-0400 (Eastern Daylight Time)
If the date string is in any other "looser" format (uses "/" or date/month is not padded with zero) it creates the date in local time zone, thus no date shifting issue.
new Date('2020/05/07')
Thu May 07 2020 00:00:00 GMT-0400 (Eastern Daylight Time)
new Date('2020-5-07')
Thu May 07 2020 00:00:00 GMT-0400 (Eastern Daylight Time)
new Date('2020-5-7')
Thu May 07 2020 00:00:00 GMT-0400 (Eastern Daylight Time)
new Date('2020-05-7')
Thu May 07 2020 00:00:00 GMT-0400 (Eastern Daylight Time)
So then one quick fix, as mentioned above, is to replace "-" with "/" in your ISO formatted Date only string.
new Date('2020-05-07'.replace('-','/'))
Thu May 07 2020 00:00:00 GMT-0400 (Eastern Daylight Time)

This solved my problem (thanks to #Sebastiao answer)
var date = new Date();
//"Thu Jun 10 2021 18:46:00 GMT+0200 (Eastern European Standard Time)"
date.toString().split(/\+|-/)[0] ; // .split(/\+|-/) is a regex for matching + or -
//"Thu Jun 10 2021 18:46:00 GMT"
var date_string_as_Y_M_D = (new Date(date)).toISOString().split('T')[0];
//2021-06-10

I just wanted to give my 2 cents on this, as this post was very helpful to figure out the issue. I don't think I've seen this solution mentioned, correct me if I'm wrong.
As it has been mentioned numerous times already here, the problem comes mainly from summer/winter time. I noticed that in January, the GMT was +1. If the time is not set, it will always be 00.00.00 (midnight), which results in going on the 23rd hour of the previous day.
If you have a dynamic date and don't care about the hour, you can set the hour using the setHours() method before using it with toISOString().
syntax:
setHours(hoursValue, minutesValue, secondsValue, msValue)
Which means that:
dynamicDate.setHours(12, 0, 0, 0)
dynamicDate.toISOString()
should hopefully work for you as even if the date is one hour ahead/behind it will still be the same day now that we're setting the hour to be noon.
More about setHours() on MDN.

You can use moment library to format the date.
https://momentjs.com/
let format1 = "YYYY-MM-DD"
let date = new Date();
console.log(moment(date).format(format1))
EDIT
The moment is now deprecated, you can use date-fns format method for formatting a date.
import { format } from 'date-fns'
format(new Date(), "yyyy-MM-dd")

You are using the ISO date string format which, according to this page, causes the date to be constructed using the UTC timezone:
Note: parsing of date strings with the Date constructor (and
Date.parse, they are equivalent) is strongly discouraged due to
browser differences and inconsistencies. Support for RFC 2822 format
strings is by convention only. Support for ISO 8601 formats differs in
that date-only strings (e.g. "1970-01-01") are treated as UTC, not
local.
If you format the text differently, such as "Jan 01 1970", then (at least on my machine) it uses your local timezone.

Storing yyyy-mm-dd in MySql Date format you must do the following:
const newDate = new Date( yourDate.getTime() + Math.abs(yourDate.getTimezoneOffset()*60000) );
console.log(newDate.toJSON().slice(0, 10)); // yyyy-mm-dd

Following Code worked for me. First I converted to date and time string to localeDateString then apply the split function on the returned string.
const dateString = "Thu Dec 29 2022 00:00:00 GMT+0500 (Pakistan Standard Time)";
const date = new Date(dateString).toLocaleDateString().split("/");
const year = new Date(dateString).getFullYear();
const month = new Date(dateString).getMonth();
console.log(new Date(`${date[2]}-${date[0]}-${date[1]}`));
// 2022-12-29T00:00:00.000Z
// Due to timezone issue, the date is one day off.
console.log(new Date("2011-09-24"));
// => 2011-09-24T00:00:00.000Z-CORRECT DATE.
console.log(new Date("2011/09/24"));
// => 2011-09-23T19:00:00.000Z -ONE DAY OFF AS BEFORE.

Using moment you can keep Offset while converting toISOString
let date = moment("2022-03-15").toISOString();
// WRONG OUTPUT 2022-03-14T18:30:00.000Z
let date = moment("2022-03-15").toISOString(true);
// CORRECT OUTPUT 2022-03-15T00:00:00.000+05:30

The following worked for me -
var doo = new Date("2011-09-24").format("m/d/yyyy");

Why does Javascript show me the wrong date?

Consider the following date object which is created in JavaScript.
var date = new Date("2017-09-07T16:46:06.000Z");
This date object should be equivalent to Sep 7 2017 4:46:06 PM
However, in the browser console, when I type the following:
console.log(date);
The following is returned:
Fri Sep 08 2017 02:46:06 GMT+1000 (E. Australia Standard Time)
The time is wrong. (It actually is today's date, but the time is completely wrong).
Key points of confusion:
My computer timezone is set to GMT+1000 (Australia/Brisbane)
When I created the date object, I did not specify the timezone, therefore it should conform to my systems timezone
When I log the date object to the console, it is still using GMT+1000 (Australia/Brisbane) but the date is different

When you created the date, you did specify a timezone. That Z at the end means Zulu or Greenwich Mean Time. Your computer is 10 hours off from GMT, so it adjusts to your local timezone for display.
If you want the date to be in your local time zone, remove the Z

var date = new Date("2017-09-07T16:46:06.000Z");
So it looks like the Z at the end of your date string is meant to represent UTC or Zulu time
var date = new Date("2017-09-07T16:46:06.000");
should be the correct solution

new Date object Javascript with 1 additional hour

I have a very strange behavior while extracting hours and minutes from a Date object. my initial object date is displaying 2017-01-16T19:00:00. here is the sample code:
var dt = new Date(date);
console.log("intial start date: "+date.format());
console.log("start date: "+dt);
but when I create a new Date object (dt) to extract hour and minute, I can see 1 more hour from the initial value....timezone seems to be correct....
here are the logs:
intial start date: 2017-01-16T19:00:00
start date: Mon Jan 16 2017 20:00:00 GMT+0100 (Romance Standard Time)
start date hours: 20 Minutes: 0
In fact I just want to extract hours and minutes from date, how can I do that with the correct hour and minutes ?

Apparently you are using fullCalendar, which uses Moment to handle dates. So when you call .format(), you call a method defined by Moment. The documentation on that method says:
As of version 1.5.0, calling moment#format without a format will default to moment.defaultFormat. Out of the box, moment.defaultFormat is the ISO8601 format YYYY-MM-DDTHH:mm:ssZ
So, by not specifying an argument to .format(), the date/time is rendered in the GMT 00:00 time zone, which is not yours. To solve this, provide a format argument, for example like this:
date.format('DD/MM/YYYY HH:mm:ss')

Javascript date object automatically add one day when creating from date string

In my javascript i want to convert date from date string.
i have string like
date = "Thu Sep 03 2015 19:30:00 GMT+0000"
Now i convert string using Date object.
var d = new Date(date);
But this gives me,
Fri Sep 04 2015 01:00:00 GMT+0530 (IST)
It automatically add one day into day. What is wrong?

It automatically add one day into day. What is wrong?
Nothing. The time you input is 19:30 GMT and the timezone on the device you're using is set to GMT+0530. Add 5 hours 30 minutes to 7:30pm and you get 01:00am the following day.
You should not use the Date constructor to parse strings, as it is inconsistent across browsers and until recently, entirely implementation dependent. Manually parse strings, or use a Date library.

Why does js subtract a day from a Date object with a certain format?

I get dates from the database in this format:
yyyy-mm-dd
When I create a javascript Date object using this string, it builds a day before the date.
You can test this in your console:
var d = new Date("2015-02-01");
d
You will get January 31st! I've tested many theories, but none answer the question.
The day is not zero-based, otherwise it would give Feb 00, not Jan 31
It's not performing a math equation, subtracting the day from the month and/or year
Date(2015-02-01) = Wed Dec 31 1969
Date("2015-01") = Wed Dec 31 2014
It is not confusing the day for the month
Date("2015-08-02") = Sat Aug 01 2015
If this were true the date would be Feb 08 2015
If you create a Date using a different format, it works fine
Date("02/01/2015") = Feb 1st, 2015
My conclusion is that js does this purposefully. I have tried researching 'why' but can't find an explanation. Why does js build dates this way, but only with this format? Is there a way around it, or do I have to build the Date, then set it to the next day?
PS: "How to change the format of the date from the db" is not what I'm asking, and that is why I'm not putting any db info here.

Some browsers parse a partial date string as UTC and some as a local time,
so when you read it the localized time may differ from one browser to another
by the time zone offset.
You can force the Date to be UTC and add the local offset if you
want the time to be guaranteed local:
1. set UTC time:
var D= new Date("2015-02-01"+'T00:00:00Z');
2. adjust for local:
D.setMinutes(D.getMinutes()+D.getTimezoneOffset());
value of D: (local Date)
Sun Feb 01 2015 00:00:00 GMT-0500 (Eastern Standard Time)
Offset will be whatever is local time.
Some differences between browsers when time zone is not specified in a parsed string:
(tested on Eastern Standard Time location)
(new Date("2015-02-01T00:00:00")).toUTCString();
Firefox 35: Sun, 01 Feb 2015 05:00:00 GMT
Chrome 40: Sun, 01 Feb 2015 00:00:00 GMT
Opera 27: Sun, 01 Feb 2015 00:00:00 GMT
IE 11: Sun, 01 Feb 2015 05:00:00 GMT
IE and Firefox set the Date as if it was local, Chrome and Opera as if it was UTC.

In javascript, Date objects are internally represented as the number of milliseconds since Jan 1st 1970 00:00:00 UTC. So instead of thinking of it as a "date" in the normal sense, try thinking of a Date object as a "point in time" represented by an integer number (without timezone).
When constructing your Date object using a string, you are actually just calling the parse function. Most date time formats (including ISO 8601) allow you to reduce the precision of a date string.
For reduced precision, any number of values may be dropped from any
of the date and time representations, but in the order from the least
to the most significant.
e.g. 2015-02-01 would represent the day February 1st 2015.
This causes a dilemma for javascript because a Date object is always accurate to the millisecond. Javascript cannot store a reduced accuracy date since it is just an integer of milliseconds since 1st Jan 1970. So it does the next best thing which is to assume a time of midnight (00:00:00) if not specified, and a timezone of UTC if not specified.
All valid javascript implementations should give the same result for this:
var d = new Date("2015-02-01");
alert(d.getTime());
1422748800000
The out-by-1-day issue comes when outputting the date either to some (often unclear) debugger or using the getter methods because the local timezone is used. In a browser, that will be your operating systems timezone. Anyone "west" of Greenwich Mean Time may see this problem because they have a negative UTC offset. Please note there are UTC equivalent functions too which use the UTC timezone, if you are really just interested in representing a date rather than a point in time.