290273 - Time in properties window is changed by timezone offset every time browser is closed

Status: VERIFIED INVALID

(Toolkit :: Downloads API, defect)

Description

[Michael Kraft [:morac]]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050317 Firefox/1.0.2
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050317 Firefox/1.0.2

If the Download Manager is set in manually clean up mode and 1 or more files
were download in a browsing session, the properties for all entries in the
Download Manager will have their time shifted by the current timezone offset
when the browser is closed and reopened.

Reproducible: Always

Steps to Reproduce:
1. In the privacy settings, make sure Download Manager download removal is set
to "manual"
2. Download one or more files.  Check their properties and the start and finish
times will be correct.
3. Close the browser and reopen.  Check the properties again and they will be
off by the current timezone offset.  For example for EDT (-4) if the files were
download at 9 PM, they will list as being downloaded at 5 PM.
4. Without downloading any files, close the browser and reopen and check the
properties, they will be the same as in step #3.
5. Download some more files, close the browser and reopen.
6. Check the properties and all the existings files will have their time
properties shifted (including the ones that were already shifted in step #3.

Actual Results:  
The start and finish times are changed by whatever the timezone offset is (-5
for EST, -8 for PST, etc) after the browser is closed and reopened.

Expected Results:  
The start and finish times should not change.

I noticed this on a NTFS filesystem.  NTFS stores all dates/times in GMT on the
disk and translates them for the system's current timezone and daylight savings
time settings.  This might have something to do with the problem. FAT32 stores
the time as as adjusted so the problem may not happen there.

FAT is a local time system
NTFS is a UTC (Universal Coordinated Time) time system

Comment 1

[Michael Kraft [:morac]]

I just tried saving a file to a FAT32 and it still had the same problem so it
might not have anything to do with NTFS.  Both my profile and firefox are both
on a NTFS drive though.

Comment 2

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(sickish, maybe slower respose)]

*** Bug 290272 has been marked as a duplicate of this bug. ***

Comment 3

[Thomas Bertels]

Reproduced
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050606
Firefox/1.0+

Comment 4

[Jo Hermans]

Wasn't this a deficiency of FAT itself ? See
<http://www.sleuthkit.org/sleuthkit/docs/skins_fat.html>, look for "Note on
Timezones".

Comment 5

[Thomas Bertels]

(In reply to comment #4)
I rather think that it's caused by the different time management between Linux
and Windows. So it's like explained in the link you provided (GMT+X for Linux,
local time for Windows) but applied to the system itself.
I think that Firefox believes that the time is stored in the GMT+X format, so it
adds the offset again when it opens it.

Comment 6

[Michael Kraft [:morac]]

(In reply to comment #5)
> (In reply to comment #4)
> I rather think that it's caused by the different time management between Linux
> and Windows. So it's like explained in the link you provided (GMT+X for Linux,
> local time for Windows) but applied to the system itself.
> I think that Firefox believes that the time is stored in the GMT+X format, so it
> adds the offset again when it opens it.

For FAT this is true, but I originally reported this on a NTFS filesystem which does store files with a timestamp GMT timestamp.  Windows XP itself adjusts what is actually displayed depending on the user specified timezone.

So a file saved in Windows NT/2k/XP to a NTFS filesystem should behave the same as one stored in Linux.

In #2 I posted though that it doesn't seem to make a difference whether the file is stored on a FAT or NTFS filesystem.

Comment 7

[Shawn Wilsher :sdwilsh]

properties dialog no longer exists in Firefox 3.

Comment 8

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to comment #7)
> properties dialog no longer exists in Firefox 3.

Verified; we leave most of this up to the system, which is of course more reliable.