437772 - wrong date is built in a few cases (core, affects xulrunner)

Status: RESOLVED DUPLICATE of bug 704486

(Core :: JavaScript Engine, defect)

Description

[Marco Balestra]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_3; en-us) AppleWebKit/525.18 (KHTML, like Gecko) Version/3.1.1 Safari/525.20
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14

new Date( 1930, 5, 1) returns "Sat May 31 1930 23:00:00 GMT+0100 (CET)",
new Date( 1947, 5, 1) returns "Sat May 31 1947 23:00:00 GMT+0100 (CET)"



Reproducible: Always

Steps to Reproduce:
1. maybe the italian timezone is needed? Don't know
2. type URL "javascript:alert( new Date( 1930, 5, 1));" and press enter
Actual Results:  
Sat May 31 1930 23:00:00 GMT+0100 (CET)

Expected Results:  
Sun Jun 01 1930 00:00:00 GMT+0200 (CEST)

discovered in XULrunner, probably it's based upon the determination of the actual timezone (see "CET" versus "CEST").

Comment 1

[Mike Shaver (:shaver -- probably not reading bugmail closely)]

Can you reproduce this with Firefox 3 RC2 (http://www.mozilla.com/en-US/firefox/all-rc.html)?

Comment 2

[Marco Balestra]

I'm downloading it right now... I can confirm, it also affects FFox 3RC2 (EN/US)

In any case the bug seems to affect the Xulrunner engine I actually use to deploy multiplatform applications.
For the time being (I only need days) I did patch my apps by creating the new dates at 12:00 hours.

Additional info: it's not only a Mac OS X issue.
Windows version of XUL engine isn't affected, while Linux *is*.

Comment 3

[Marco Balestra]

(In reply to comment #2)

> I'm downloading it right now... I can confirm, it also affects FFox 3RC2
> (EN/US)

The bug is still there with the final version of Firefox 3 - Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9) Gecko/2008061004 Firefox/3.0

Comment 4

[André Bargull [:anba]]

Dup forward to bug 1233809

Comment 5

[ememisya]

The bug I've reported is due to historical DST in timezones not being observed on the Windows implementation of Firefox.  FF displays historical DST correctly on Linux systems, yet on Windows it seems to apply today's DST to all dates in the past.  Chrome and a handful of other browsers were also affected at the time I've filed the issue, I have *only* confirmed this bug to exist on Windows. Edge browser however must be using the correct system libraries on Windows as it works as expected (I wonder what native code it's using for DST offset on Date). I am not certain if DUPLICATE resolution is appropriate in this case, were you able to confirm Mac implementation is afflicted in the same manner?

Comment 6

[André Bargull [:anba]]

Well, we can also dup this forward to bug 704486, bug 1122571, bug 1385643, or ... Yes, there are many duplicate bugs about date/time issues before 1970 (start of the Unix epoch). And there are also a couple of duplicates for date/time issues on Windows (bug 1330307, bug 1335818, ...). :-)

So, let's close this one as a dup of 704486 instead of 1233809.