Parse date without timezone javascript

Question 1

The date is parsed correctly, it's just toString that converts it to your local timezone:

let s = "2005-07-08T11:22:33+0000";
let d = new Date(Date.parse(s));

// this logs for me 
// "Fri Jul 08 2005 13:22:33 GMT+0200 (Central European Summer Time)" 
// and something else for you

console.log(d.toString()) 

// this logs
// Fri, 08 Jul 2005 11:22:33 GMT
// for everyone

console.log(d.toUTCString())

Javascript Date object are timestamps - they merely contain a number of milliseconds since the epoch. There is no timezone info in a Date object. Which calendar date (day, minutes, seconds) this timestamp represents is a matter of the interpretation (one of to...String methods).

The above example shows that the date is being parsed correctly - that is, it actually contains an amount of milliseconds corresponding to "2005-07-08T11:22:33" in GMT.

Question 2

I have the same issue. I get a date as a String, for example: '2016-08-25T00:00:00', but I need to have Date object with correct time. To convert String into object, I use getTimezoneOffset:

var date = new Date('2016-08-25T00:00:00')
var userTimezoneOffset = date.getTimezoneOffset() * 60000;
new Date(date.getTime() - userTimezoneOffset);

getTimezoneOffset() will return ether negative or positive value. This must be subtracted to work in every location in world.

Question 3

I ran into the same problem and then remembered something wonky about a legacy project I was working on and how they handled this issue. I didn't understand it at the time and didn't really care until I ran into the problem myself

var date = '2014-01-02T00:00:00.000Z'
date = date.substring(0,10).split('-')
date = date[1] + '-' + date[2] + '-' + date[0]

new Date(date) #Thu Jan 02 2014 00:00:00 GMT-0600

For whatever reason passing the date in as "01-02-2014" sets the timezone to zero and ignores the user's timezone. This may be a fluke in the Date class but it existed some time ago and exists today. And it seems to work cross-browser. Try it for yourself.

This code is implemented in a global project where timezones matter a lot but the person looking at the date did not care about the exact moment it was introduced.

Question 4

Since it is really a formatting issue when displaying the date (e.g. displays in local time), I like to use the new(ish) Intl.DateTimeFormat object to perform the formatting as it is more explicit and provides more output options:

const dateOptions = { timeZone: 'UTC', month: 'long', day: 'numeric', year: 'numeric' };

const dateFormatter = new Intl.DateTimeFormat('en-US', dateOptions);
const dateAsFormattedString = dateFormatter.format(new Date('2019-06-01T00:00:00.000+00:00'));

console.log(dateAsFormattedString) // "June 1, 2019"

As shown, by setting the timeZone to 'UTC' it will not perform local conversions. As a bonus, it also allows you to create more polished outputs. You can read more about the Intl.DateTimeFormat object in Mozilla - Intl.DateTimeFormat.

The same functionality can be achieved without creating a new Intl.DateTimeFormat object. Simply pass the locale and date options directly into the toLocaleDateString() function.

const dateOptions = { timeZone: 'UTC', month: 'long', day: 'numeric', year: 'numeric' };
const myDate = new Date('2019-06-01T00:00:00.000+00:00');
myDate.toLocaleDateString('en-US', dateOptions); // "June 1, 2019"

Question 5

I found JavaScript Date Object and Time Zones | Fixing an "off by 1 day" bug on YouTube. This fixes/resets the offset for the local timezone. There's a great explanation to this problem in the video.

// date as YYYY-MM-DDT00:00:00Z

let dateFormat = new Date(date)

// Methods on Date Object will convert from UTC to users timezone
// Set minutes to current minutes (UTC) + User local time UTC offset

dateFormat.setMinutes(dateFormat.getMinutes() + dateFormat.getTimezoneOffset())

// Now we can use methods on the date obj without the timezone conversion

let dateStr = dateFormat.toDateString();

Question 6

The Date object itself will contain timezone anyway, and the returned result is the effect of converting it to string in a default way. I.e. you cannot create a date object without timezone. But what you can do is mimic the behavior of Date object by creating your own one. This is, however, better to be handed over to libraries like moment.js.

Question 7

Date in JavaScript is just keeping it simple inside, so the date-time data is stored in UTC Unix epoch (milliseconds or ms).

If you want to have a "fixed" time that doesn't change in whatever timezone you are on the earth, you can adjust the time in UTC to match your current local timezone and save it. And when retrieving it, in whatever your local timezone you are in, it will show the adjusted UTC time based on the one who saved it and then add the local timezone offset to get the "fixed" time.

To save date (in ms):

toUTC(datetime) {
  const myDate = (typeof datetime === 'number')
    ? new Date(datetime)
    : datetime;

  if (!myDate || (typeof myDate.getTime !== 'function')) {
    return 0;
  }

  const getUTC = myDate.getTime();
  const offset = myDate.getTimezoneOffset() * 60000; // It's in minutes so convert to ms
  return getUTC - offset; // UTC - OFFSET
}

To retrieve/show date (in ms):

fromUTC(datetime) {
  const myDate = (typeof datetime === 'number')
    ? new Date(datetime)
    : datetime;

  if (!myDate || (typeof myDate.getTime !== 'function')) {
    return 0;
  }

  const getUTC = myDate.getTime();
  const offset = myDate.getTimezoneOffset() * 60000; // It's in minutes so convert to ms
  return getUTC + offset; // UTC + OFFSET
}

Then you can:

const saveTime = new Date(toUTC(Date.parse("2005-07-08T00:00:00+0000")));
// SEND TO DB....

// FROM DB...
const showTime = new Date(fromUTC(saveTime));

Question 8

You can use this code

var stringDate = "2005-07-08T00:00:00+0000";
var dTimezone = new Date();
var offset = dTimezone.getTimezoneOffset() / 60;
var date = new Date(Date.parse(stringDate));
date.setHours(date.getHours() + offset);

Question 9

Here's a simple solution:

const handler1 = {
  construct(target, args) {
    let newDate = new target(...args);
    var tzDifference = newDate.getTimezoneOffset();
    return new target(newDate.getTime() + tzDifference * 60 * 1000);
  }
};

Date = new Proxy(Date, handler1);

Question 10

The solution is almost the same as @wawka's, however it handles different timezones with plus and minus sings using Math.abs:

const date = new Date("2021-05-24T22:00:18.512Z")
const userTimezoneOffset = Math.abs(date.getTimezoneOffset() * 60000);
new Date(date.getTime() - userTimezoneOffset);

Question 11

I would personally prefer @wawka's answer, however, I also came up with a not so clean trick to solve this problem, which is simpler and can work if you are sure about the format of the strings you want to convert.

Look at the code snippet below:

var dateString = '2021-08-02T00:00:00'

var dateObj = new Date(dateString + 'Z')
console.log("No Timezone manipulation: ", dateObj)

var dateObjWithTZ = new Date(dateString)
console.log("Normal conversion: ", dateObjWithTZ)

This works in this case, because adding a Z to the end of the date time string will make JS treat this string to be a UTC date string, so it does not add timezone difference to it.

Question 12

This is the solution that I came up with for this problem which works for me.

library used: momentjs with plain javascript Date class.

Step 1. Convert String date to moment object (PS: moment retains the original date and time as long as toDate() method is not called):

const dateMoment = moment("2005-07-08T11:22:33+0000");

Step 2. Extract hours and minutes values from the previously created moment object:

  const hours = dateMoment.hours();
  const mins = dateMoment.minutes();

Step 3. Convert moment to Date(PS: this will change the original date based on the timezone of your browser/machine, but don't worry and read step 4.):

  const dateObj = dateMoment.toDate();

Step 4. Manually set the hours and minutes extracted in Step 2.

  dateObj.setHours(hours);
  dateObj.setMinutes(mins);

Step 5. dateObj will now have show the original Date without any timezone difference. Even the Daylight time changes won't have any effect on the date object as we are manually setting the original hours and minutes.

Hope this helps.

Question 13

(new Date().toString()).replace(/ \w+-\d+ $.*$$/,"")

This will have output: Tue Jul 10 2018 19:07:11

(new Date("2005-07-08T11:22:33+0000").toString()).replace(/ \w+-\d+ $.*$$/,"")

This will have output: Fri Jul 08 2005 04:22:33

Note: The time returned will depend on your local timezone

Question 14

There are some inherent problems with date parsing that are unfortunately not addressed well by default.

-Human readable dates have implicit timezone in them
-There are many widely used date formats around the web that are ambiguous

To solve these problems easy and clean one would need a function like this:

>parse(whateverDateTimeString,expectedDatePattern,timezone)
"unix time in milliseconds"

I have searched for this, but found nothing like that!

So I created: https://github.com/zsoltszabo/timestamp-grabber

Enjoy!