377366 - GetTimezoneoffset returns wrong value when the system is kept to mid-atlantic timezone

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

[Durga Prasad K]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.11) Gecko/20070312 Firefox/1.5.0.11
Build Identifier: 1.5.0.11

when I changed the timezone of my XP system to mid-atlantic, the timezoneoffset value is being returned as 60... however it should be 120.

(new Date()).getTimezoneOffset() when the system timezone is set to mid-atlantic

Mid-atlantic timezoneoffset will always should be 120 not depending on DST. No DST applicable.



Reproducible: Always

Steps to Reproduce:
Change the system timezone to mid-atlantic and 
have this (new Date()).getTimezoneOffset() in a script and run. It will return 60 instead of 120.
Actual Results:  
value is 60

Expected Results:  
value should be 120

Comment 1

[:Gavin Sharp [email: [e-mail]]]

This sounds like a duplicate of bug 285615. Durga, can you confirm? Does restarting the browser after changing time zones fix the problem?

Comment 2

[Durga Prasad K]

Its not a duplicate as after the restart of the firefox too, it is happening.

I feel it is happening only for that mid-atlantic timezone and is too specific.

Comment 3

[André Bargull [:anba]]

Microsoft deprecated the Mid-Atlantic time zone in https://support.microsoft.com/en-us/kb/2904266, and in current Windows versions (tested Win7 and Win10) it's no longer possible to select this time zone. Therefore resolving as Won't fix.