Parse date without timezone javascript

女生的网名这么多〃 提交于 2019-11-26 13:05:48

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

> new Date(Date.parse("2005-07-08T11:22:33+0000"))
Fri Jul 08 2005 13:22:33 GMT+0200 (CEST)
> new Date(Date.parse("2005-07-08T11:22:33+0000")).toUTCString()
"Fri, 08 Jul 2005 11:22:33 GMT"

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.

wawka

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.

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.

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.

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);

Just a generic note. a way to keep it flexible.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date

We can use getMinutes(), but it return only one number for the first 9 minutes.

let epoch = new Date() // Or any unix timestamp

let za = new Date(epoch),
    zaR = za.getUTCFullYear(),
    zaMth = za.getUTCMonth(),
    zaDs = za.getUTCDate(),
    zaTm = za.toTimeString().substr(0,5);

console.log(zaR +"-" + zaMth + "-" + zaDs, zaTm)
Date.prototype.getDate()
    Returns the day of the month (1-31) for the specified date according to local time.
Date.prototype.getDay()
    Returns the day of the week (0-6) for the specified date according to local time.
Date.prototype.getFullYear()
    Returns the year (4 digits for 4-digit years) of the specified date according to local time.
Date.prototype.getHours()
    Returns the hour (0-23) in the specified date according to local time.
Date.prototype.getMilliseconds()
    Returns the milliseconds (0-999) in the specified date according to local time.
Date.prototype.getMinutes()
    Returns the minutes (0-59) in the specified date according to local time.
Date.prototype.getMonth()
    Returns the month (0-11) in the specified date according to local time.
Date.prototype.getSeconds()
    Returns the seconds (0-59) in the specified date according to local time.
Date.prototype.getTime()
    Returns the numeric value of the specified date as the number of milliseconds since January 1, 1970, 00:00:00 UTC (negative for prior times).
Date.prototype.getTimezoneOffset()
    Returns the time-zone offset in minutes for the current locale.
Date.prototype.getUTCDate()
    Returns the day (date) of the month (1-31) in the specified date according to universal time.
Date.prototype.getUTCDay()
    Returns the day of the week (0-6) in the specified date according to universal time.
Date.prototype.getUTCFullYear()
    Returns the year (4 digits for 4-digit years) in the specified date according to universal time.
Date.prototype.getUTCHours()
    Returns the hours (0-23) in the specified date according to universal time.
Date.prototype.getUTCMilliseconds()
    Returns the milliseconds (0-999) in the specified date according to universal time.
Date.prototype.getUTCMinutes()
    Returns the minutes (0-59) in the specified date according to universal time.
Date.prototype.getUTCMonth()
    Returns the month (0-11) in the specified date according to universal time.
Date.prototype.getUTCSeconds()
    Returns the seconds (0-59) in the specified date according to universal time.
Date.prototype.getYear()
    Returns the year (usually 2-3 digits) in the specified date according to local time. Use getFullYear() instead. 

(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

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.

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!

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