600320 - Doesn't Correctly Handle New Zealand Daylight Savings Time

Status: RESOLVED DUPLICATE of bug 591845

(Firefox :: General, defect)

Description

[mozilla]

User-Agent:       Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; InfoPath.1; FDM; OfficeLiveConnector.1.3; OfficeLivePatch.0.0)
Build Identifier: Mozilla/5.0 (Windows NT 5.1; rv:2.0b6) Gecko/20100101 Firefox/4.0b6

Since New Zealand went into Daylight Savings time (GMT + 13) sites that use this information (especially facebook) have been functioning incorrectly. I believe firefox has been reporting the time offset as GMT -11 instead of GMT + 13. 

Using the command javascript:Alert(new Date()) reports "Tue Sep 28 2010 09:09:13 GMT-1100 (New Zealand Standard Time)" at the moment, which is incorrect, it should be "Wed Sep 29 2010 09:09:13 GMT+1300 (New Zealand Standard Time)".

If daylight savings time is turned off (in Windows) the time offset goes to GMT + 12 (if the Javascript command is put into Firefox), I also tried a couple of other time zones (Australia), and the offset was displayed correctly, so the issue is specifically with New Zealand Daylight Savings Time.

Reproducible: Always

Steps to Reproduce:
1. Set time to New Zealand Time Zone, with Daylight Savings Turned on.
2. Run command javascript:alert(new Date())
3. Check what the offset after GMT in the window that appears is.