1

I have a snippet code in javascript as shown below:

$(document).ready(function () {    
    var day1 = new Date();
});

Now I open a browser (in this case I use FireFox) and the current TimeZone of my computer is UTC +10:00 Hobart. Then I view the day1 javascript variable in debug mode, it displays its value as image shown below. enter image description here

The TimeZone name of UTC+10:00 Hobart is Tasmania Standard Time. FF gets the correct name and as my expected too.

Next, I will chang the TimeZone on my computer to UTC+10:00 Canberra, Melbourne, Sydney while FF browser is being opened. Then I refresh FF browser by pressing Ctrl+F5 and view day1's value in debug mode again.

enter image description here

As you can see, FF updated the new correct TimeZone name as AUS Eastern Standard Time. It worked as my expected too.

MS Edge and IE worked as the same way with FF.

BUT, Chrome worked in a different way.

enter image description here

The new TimeZone name that Chrome returns to me is Local Daylight Time, not AUS Eastern Standard Time as my expected and as the other browsers (FF, MS Edge, IE) did.

Why does not Chrome return "AUS Eastern Standard Time" name?

Is there any way can solve this case for Chrome?

NoName
  • 877
  • 12
  • 28

1 Answers1

4

Unfortunately, the implementation of time zone name is not standardized. The ECMAScript spec allows it to be anything the vendor wants it to be. It's not even just different across browsers, but also across different versions of the browser, and across operating systems.

From ECMA-262 (5.1) Section 15.9.5.2 (emphasis mine)

Date.prototype.toString()

This function returns a String value. The contents of the String are implementation-dependent, but are intended to represent the Date in the current time zone in a convenient, human-readable form.

If what you're trying to do is to detect the user's time zone, there is a newer standard for retrieving the time zone name, as an IANA time zone identifier (ex, Australia/Sydney), which you can do like this:

Intl.DateTimeFormat().resolvedOptions().timeZone

However, not all browsers have implemented this yet. There are libraries that can guess at it though, which you can read about here.

Community
  • 1
  • 1
Matt Johnson-Pint
  • 230,703
  • 74
  • 448
  • 575
  • Thanks for your information, Matt. I think I should contact Chrome developer directly and discuss about this issue with them to find a solution or work around solution. My clients are experiecing this problem now, and you know, they prefer using Chrome than other browser. So I have to fix it. =)) – NoName Oct 06 '16 at 07:04
  • 1
    @PhucNguyen—when Matt says "*the implementation of time zone name is not standardized*" he means everywhere, not just ECMAScript. There are various naming schemes, and no standard, though there are [*de facto*](https://www.google.com.au/search?client=safari&rls=en&q=define+de+facto&ie=UTF-8&oe=UTF-8&gfe_rd=cr&ei=Otb2V5bnO6rM8gfQwYTQAQ) standards like [*IANA*](https://www.iana.org/time-zones) and [*military*](https://en.wikipedia.org/wiki/List_of_military_time_zones) designators. – RobG Oct 06 '16 at 22:53
  • @RobG: Thank you very much for your detailed explanation. :D. I contacted Chrome developer, and they are now reviewing my question. They will give me a feedback which the problem is a bug or not later. By the way, I think there should be a workaround solution to get my expected timezone name as the post said: http://stackoverflow.com/questions/18246547/get-name-of-time-zone/18252251#18252251 – NoName Oct 07 '16 at 08:55