Unable to find timezone abbreviation from Date.prototype.toString()

Hello I came across the moment.js site via a forum and clicked my way through it, when I came across the unit test - which failed 2 tests what I want to report here:

UserAgent:
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.77 Safari/535.7 (Chrome 16.0.912.77 m)

Timezone:
UTC+1

Failed tests (# 28):
http://pastebin.com/bQsDuxdH

*Title edited by timrwood

[timrwood]

Hmm, looks like the timezone abbreviation is failing. Sorry to do remote debugging, but what is the output of the following in chrome?

new Date().toString()

Also, what is the name of the timezone you are in?

[Sertion]

I get the same error in the unit-tests and I'm in UTC+1 (previously known as GMT+1) as well.

new Date().toString() prints "Sat Feb 11 2012 02:15:10 GMT+0100" in Firefox 10, "Sat Feb 11 2012 02:18:29 GMT+0100 (W. Europe Standard Time)" in Chrome 16 and "Sat Feb 11 02:18:59 UTC+0100 2012" in Internet Explorer 9

[timrwood]

Hmm, I was afraid of this. The problem is that Date.prototype.toString returns such different results. That is the only place to get the timezone name (PST, CST, EST, etc). If this method is not returning any timezone information (as is the case with FF10 and IE9, there is no way to get it.

Perhaps it's time to depreciate? Or is it acceptable to just note the issue in the docs?

[korywka]

4318 passed, 2 failed. 2715 milliseconds.

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11

UTC +2 (Kyiv, Ukraine)

format timezone 2 passed,2 failed.
---> Something like "PST"
AssertionError: ---> Something like "PST"
at Object.ok (http://momentjs.com/js/tests.js?_=120203_183019:1526:39)
at http://momentjs.com/js/tests.js?_=120203_183019:2413:14
at Object.runTest (http://momentjs.com/js/tests.js?_=120203_183019:1702:9)
at http://momentjs.com/js/tests.js?_=120203_183019:1748:25
at http://momentjs.com/js/tests.js?_=120203_183019:1006:13
at http://momentjs.com/js/tests.js?_=120203_183019:616:13
at http://momentjs.com/js/tests.js?_=120203_183019:627:25
at http://momentjs.com/js/tests.js?_=120203_183019:1008:17
at http://momentjs.com/js/tests.js?_=120203_183019:1589:17
---> Something like "PST"
AssertionError: ---> Something like "PST"
at Object.ok (http://momentjs.com/js/tests.js?_=120203_183019:1526:39)
at http://momentjs.com/js/tests.js?_=120203_183019:2414:14
at Object.runTest (http://momentjs.com/js/tests.js?_=120203_183019:1702:9)
at http://momentjs.com/js/tests.js?_=120203_183019:1748:25
at http://momentjs.com/js/tests.js?_=120203_183019:1006:13
at http://momentjs.com/js/tests.js?_=120203_183019:616:13
at http://momentjs.com/js/tests.js?_=120203_183019:627:25
at http://momentjs.com/js/tests.js?_=120203_183019:1008:17
at http://momentjs.com/js/tests.js?_=120203_183019:1589:17
+02:00 ---> Something like "+07:30"
+0200 ---> Something like "+0700"

[korg250]

I also get the same failing test # 28. My timezone is GMT -3.

Agent:
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.66 Safari/535.11

Failed test: http://pastebin.com/dsWHMF3h

.:.

Agent:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2
or
Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; Zune 4.7; .NET4.0E)

Failed test: http://pastebin.com/6t6JP9fu

[timrwood]

So looks like this is happening in UTC+1, UTC+2, and UTC-3.

Unfortunately, there is now way to fix this. It depends on hacking apart the Date().toString() output, and if there is no timezone information available in that string, there is no way to get that information.

I'm going to depreciate this feature and maybe make a plugin that has more reliable (although perhaps less accurate) results. It probably should be something like https://github.com/mde/timezone-js.