How does FTP "adjust for daylight saving changes" work?

Help & Support
1

Hi,

When I copy a file via FTP to our FTP server - then the time shown in DO is not the same:

I'm living in AUSTRIA / Vienna - currently we have UTC+02:00 and the daylight time period (so normal time is UTC+01:00).

Current time is:
UTC: 09:30:00
Local: 11:30:00

Under Windows clock we must have set or the following is set (and correctly):

  • Under Date & Time will be shown: "Current timezone: W. Europe Daylight Time"
  • Time Zone:
    (GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna

And: "Automatically adjust clock for daylight saving changes" is selected.

So - all is correctly - here in the office (bank) and at home.

For the FTP server - it's all the same:
Tue May 12 11:34:57 CEST 2009
CEST = Central European Summer Time (the same as above).

The FTP definition (SFTP!):
"Adjust directory and file dates for the site time zone" is selected.
Time Zone: (GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna
"Adjust for daylight saving changes" is selected.

When I copy the file from Windows with the modify time 09:58:00 to the FTP server, DO shows 08:58:00.

Why? (why not 09:58:00)

What are the correct settings?

2

AND:

When I select FTP / Site Properties (to change the current session),

deactive "Adjust for daylight saving changes", click OK, reload the directory,

the file time is still 08:58:00.

AND THEN AGAIN

When I select FTP / Site Properties (to change the current session),

ACTIVE (!) "Adjust for daylight saving changes", click OK, reload the directory,

the file time is still 09:58:00.

So for me it's a bug in DO, right?

When I connect to the FTP - the wrong times will be shown.

When I make changes during the session (deactive, active), the correct times will be shown.

3

Type error:

should be:

the file time is now 09:58:00 (correct).

Sorry,

4

I can't seem to reproduce the problem so far on my Vista machine.

It sounds like it could be the Windows/NTFS issue where timestamps from before the DST change-over appear to move by an hour after the changeover. (The timestamps are stored as UTC and converted to local time at the current offset from UTC, rather than what the offset was at the time of the stamp. i.e. The same UTC timestamp on a file can be reported differently in and out of DST.) That may not happen to the timestamps that Opus shows on FTP sites as those timestamps may be converted to local time via a different method to the one which NTFS uses.

If it is that, and you're using XP or Win2k, then the way the OS reports/converts NTFS timestamps may have changed in Vista. That could explain why I can't reproduce it, even after setting my computer and FTP bookmark to the same +1+DST timezone and downloading files from periods in and out of DST. Maybe I've done something wrong in my repro steps though.

Edit: Added a link to a good description of the Windows/NTFS DST issue.