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");
So I have this date returned from an API:
"2014-08-07T00:00Z"
And the results from new Date("2014-08-07T00:00Z") equal Wed Aug 06 2014 20:00:00 GMT-0400 (EDT) and .getDay() on that date gives me 3.
Why is it going from August 7th, to 6th, and the getDay returns 3?
Basically I'm trying to turn the API return date into english.
days[d.getDay()]+", "+months[d.getMonth()]+" "+getOrdinal(d.getDay())+" "+formatAMPM(d)
(aka "Wednesday, August 3rd 8:00 pm")
console.log(d,data[i].startDate, d.getDay());
//yields
// Wed Aug 06 2014 20:00:00 GMT-0400 (EDT) "2014-08-07T00:00Z" 3
days is just an array of text days, as is months, getOrdinal is a function that gives the text st or nd or rd on the day, and formatAMPM is pretty obvious.
.getDay() returns the day of the week. I think you'd expect .getDate()
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getDay
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getDate
That's why you're seeing that it is a Wednesday.
The result for me of new Date("2014-08-07T00:00Z") is Wed Aug 06 2014 18:00:00 GMT-0600 (MDT). This is because dates are converted to your local timezone when constructed
I don't think that there is any problem here.
Your date is 2014-08-07T00:00Z, with Z meaning Zulu Time Zone (equivalent to UTC), and using new Date() on it will convert to you local time, here GMT-4, that is why you are getting 4 hours difference.
And For the "3", the getDay() method returns the day of the week, wednesday in your case.
I have just noticed some strange behavior in one of my Arrays. I am sure the issue is with how Javascript stores object references in arrays. I will demonstrate the issue with a bit of code I posted as an answer to another question on SO. The code, just loops to get todays date and the 6 previous dates of the month, pretty self explanatory.
var dates = [];
var date = new Date();
for (var i = 0; i < 7; i++){
var tempDate = new Date();
tempDate.setDate(date.getDate()-i);
dates.push(tempDate);
}
console.log(dates);
Output: [Thu Jun 05 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Wed Jun 04 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Tue Jun 03 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Mon Jun 02 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Sun Jun 01 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Sat May 31 2014 14:54:14 GMT+0100 (GMT Daylight Time),
Fri May 30 2014 14:54:14 GMT+0100 (GMT Daylight Time)]
This is correct, and is expected, as tempDate is continually recreated as a new Date object inside of the loop.
When I take tempDate out of the loop however, it seems to update all of the objects in the array every iteration of the loop (also the loop seems to go one Month and 1 day too far to 29th apr):
var dates = [];
var date = new Date();
var tempDate = new Date();
for (var i = 0; i < 7; i++){
tempDate.setDate(date.getDate()-i);
dates.push(tempDate);
}
console.log(dates);
Output: [Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time),
Tue Apr 29 2014 14:52:21 GMT+0100 (GMT Daylight Time)]
So the two questions I pose are:
Why does the object stored in the array keep mutating with every
iteration? (I suspect this is because of the way Javascript is
storing the references to the object, but an explanation would be
nice)
Why does the loop run one too far in the second bit of code? The first example shows the loop ends after 7 successful iterations, on May the 30th (7 days in the past), the second example shows the resultant date after the iterations as the 29th april - more than a month into the past. Why?
edit: I have a rudimentary jsfiddle, to allow testing the code.
var tempDate = new Date(); creates new object. so in this example:
var array = [tempDate,tempDate,tempDate,tempDate,tempDate];
array[0] is same object as array[1]
this is just how objects works in almost every programming language:
var a = tempDate;
var b = tempDate;
var c = b;
(in above example a, b, c, and tempDate is same thing)
Regarding question 2:
please have a look at this fiddle http://jsfiddle.net/Mqnmm/
with new object tempDate is always today, then you apply setDate()
with old object, before last literation date is Sat, 31 May 2014 14:23:34 GMT, then you apply tempDate.setDate(-1) which sets date to last N days of previous month
Subtract days from a date in JavaScript please check Rob Dawley`s answer to properly adjust dates
So I have this JS-code:
var d1 = new Date();
d1.setFullYear(2014);
d1.setMonth(1);
d1.setDate(1);
Should be Feb-01-2014, right? Only it's not... It returns Mar-01-2014 (actually, the full value is "Sat Mar 01 2014 20:54:29 GMT+0100 (Romance Standard Time)"). What the hell? Same thing happens with any other date value.
If I use this code, however, it works fine:
var d1 = new Date(2014, 1, 1, 0, 0, 0, 0);
The result is: Sat Feb 01 2014 00:00:00 GMT+0100 (Romance Standard Time)
Any ideas what's going on?
Here's what's happening, line for line:
You create a new date object with today's date.
var d1 = new Date(); // d1 = 2014-04-30
Then you set the year to 2014, which it already is, so nothing really happens.
d1.setFullYear(2014); // d1 = 2014-04-30
Here's the tricky part, because now you change the month to February. But this would make the date February the 30th (2014-02-30) which doesn't exist, so the JavaScript will try to find the closest valid date which is first of March (2014-03-01).
d1.setMonth(1); // d1 = 2014-02-30 is not valid so JS makes it 2014-03-01
Then you set the day to the first day of the month, which it already is, so nothing really happens here either.
d1.setDate(1) // d1 = 2014-03-01
You need to call setDate first. Basically it's grabbing the month and using the current date and since February doesn't have a 30th, it's defaulting to March.
Better to initialize Date, rather than have it default to the current date.
var d1 = new Date(0); // 1 January 1970 00:00:00 UTC
Try this:
d1.setFullYear(2014);
d1.setDate(1);
d1.setMonth(1);
What you were doing:
d1.setFullYear(2014); // change year to 2014 (30 Apr 2014 -> 30 Apr 2014)
d1.setMonth(1); // change month to 1 (30 Apr 2014 -> 30 Feb 2014, really 2 Mar 2014)
d1.setDate(1); // change day of month to 1 (2 Mar 2014 -> 1 Mar 2014)
By setting the date first, you're changing the date to 1 Apr 2014 before changing the month.