What changed the last-modified time stamp of these files?

[Stan Hilliard]

I have two sets of the same old files, one set copied from the other
on 3/5/2007 12:53 PM -- prior to the recent change to standard time. I
know the date/time of the copy because the date/time of the created
folders. The file date/times of all files are all exactly one hour
apart.

The copied files are "later". For example, one original is 1/28/2001
1:25 AM, its copy is 1/28/2001 2:25 AM.

When I copy the "copy" back over the original, it retains its changed
time of 2:25 AM.

When I noticed this it surprised me. Can anyone explain why this
happens?

Here are some specifics:
I copied 1.075 folder containing 15,149 files.

The original files were on a Win98SE PC.

The copying was over an Ethernet cable to a Win XP home PC.

The copies were made during central standard time (March 5). I did not
examine the date/times of the files or the computer settings at that
time.

Current situation 4/27/2007 -- during daylight saving time:
Explorer shows the copies on the XP to be ahead by one hour. The
clocks of both machines say the same time. The Win XP PC clock
properties say explicitly that it is on central daylight time. The
Win98SE PC clock properties say (GMT-06:00) Central Time, with a check
before "automatically adjust for daylight saving changes."

Explorer shows the "copied back" file on the Win98SE to have a time 1
hour later than the original it replaced.

Do operating systems change the last-modified dates of files? What
explains this?
Stan Hilliard

 

[Stan Hilliard]

I have two sets of the same old files, one set copied from the other
on 3/5/2007 12:53 PM -- prior to the recent change to standard time.

CORRECTION: I meant "prior to the recent change FROM standard time
that happened on Sunday March 11,2007.."

 

[BillW50]

CORRECTION: I meant "prior to the recent change FROM standard time
that happened on Sunday March 11,2007.."

I don't know Stan... I did read that Win9x systems don't have the bits
necessary to store odd number seconds or was it minutes in the time. I
read this having to do with correcting the new daylight saving time. I
think it was on MS Knowledgebase somewhere.

Say, on another subject. You know there is a patch to fix the daylight
saving time for Windows 9x machines, right? It is at:

http://www.intelliadmin.com/blog/2007/02/windows-98-me-dst-patch.html

 

[Rock]

I have two sets of the same old files, one set copied from the other
on 3/5/2007 12:53 PM -- prior to the recent change to standard time. I
know the date/time of the copy because the date/time of the created
folders. The file date/times of all files are all exactly one hour
apart.

The copied files are "later". For example, one original is 1/28/2001
1:25 AM, its copy is 1/28/2001 2:25 AM.

When I copy the "copy" back over the original, it retains its changed
time of 2:25 AM.

When I noticed this it surprised me. Can anyone explain why this
happens?

Here are some specifics:
I copied 1.075 folder containing 15,149 files.

The original files were on a Win98SE PC.

The copying was over an Ethernet cable to a Win XP home PC.

The copies were made during central standard time (March 5). I did not
examine the date/times of the files or the computer settings at that
time.

Current situation 4/27/2007 -- during daylight saving time:
Explorer shows the copies on the XP to be ahead by one hour. The
clocks of both machines say the same time. The Win XP PC clock
properties say explicitly that it is on central daylight time. The
Win98SE PC clock properties say (GMT-06:00) Central Time, with a check
before "automatically adjust for daylight saving changes."

Explorer shows the "copied back" file on the Win98SE to have a time 1
hour later than the original it replaced.

Do operating systems change the last-modified dates of files? What
explains this?
Stan Hilliard

On an NTFS volume file time stamps are changed with a daylight savings time
change to show the new time. So when they were copied to XP Home, it must
be to an NTFS formatted drive, and the time stamps were changed when the DST
change came. It doesn't happen on a FAT formatted drive.

 

[Stan Hilliard]

I have two sets of the same old files, one set copied from the other
on 3/5/2007 12:53 PM -- prior to the recent change to standard time. I
know the date/time of the copy because the date/time of the created
folders. The file date/times of all files are all exactly one hour
apart.

The copied files are "later". For example, one original is 1/28/2001
1:25 AM, its copy is 1/28/2001 2:25 AM.

When I copy the "copy" back over the original, it retains its changed
time of 2:25 AM.

When I noticed this it surprised me. Can anyone explain why this
happens?

Here are some specifics:
I copied 1.075 folder containing 15,149 files.

The original files were on a Win98SE PC.

The copying was over an Ethernet cable to a Win XP home PC.

The copies were made during central standard time (March 5). I did not
examine the date/times of the files or the computer settings at that
time.

Current situation 4/27/2007 -- during daylight saving time:
Explorer shows the copies on the XP to be ahead by one hour. The
clocks of both machines say the same time. The Win XP PC clock
properties say explicitly that it is on central daylight time. The
Win98SE PC clock properties say (GMT-06:00) Central Time, with a check
before "automatically adjust for daylight saving changes."

Explorer shows the "copied back" file on the Win98SE to have a time 1
hour later than the original it replaced.

Do operating systems change the last-modified dates of files? What
explains this?
Stan Hilliard

On an NTFS volume file time stamps are changed with a daylight savings time
change to show the new time. So when they were copied to XP Home, it must
be to an NTFS formatted drive, and the time stamps were changed when the DST
change came. It doesn't happen on a FAT formatted drive.
Rock [MS-MVP User/Shell]

That explains it. The originals are in on a FAT32 volume and the
copies on FTFS.

I see that in [clock properties] when I uncheck and check "adjust for
daylight saving", Explorer's file dates change. (NTFS)
Stan Hilliard

 

[Bill in Co.]

But why should they be? What kind of "design logic" is that? It
sounds crazy! (although I believe you, I don't understand WHY that would
have been designed into it in the first place; when a file is date/time
stamped, THAT stamp should be in concrete, and not subject to the whims of
DST or no DST)

 

[Rock]

But why should they be? What kind of "design logic" is that? It
sounds crazy! (although I believe you, I don't understand WHY that would
have been designed into it in the first place; when a file is date/time
stamped, THAT stamp should be in concrete, and not subject to the whims of
DST or no DST)

Time stamp changes with daylight savings
http://support.microsoft.com/kb/129574/en-us

 

[Bill in Co.]

Time stamp changes with daylight savings
http://support.microsoft.com/kb/129574/en-us

I wasn't disputing that it did (and I seem to recall this problem too,
between work and home), but was asking WHY it was designed this way, on the
NT systems (as an offset from GMT). In other words, why was NT designed
that way - (so different from the other operating systems, that don't have
this problem)?

 

[Rock]

I wasn't disputing that it did (and I seem to recall this problem too,
between work and home), but was asking WHY it was designed this way, on
the
NT systems (as an offset from GMT). In other words, why was NT
designed
that way - (so different from the other operating systems, that don't have
this problem)?

Ask the designer(s).

 

[Bill Blanton]

I wasn't disputing that it did (and I seem to recall this problem too,
between work and home), but was asking WHY it was designed this way, on the
NT systems (as an offset from GMT). In other words, why was NT designed
that way - (so different from the other operating systems, that don't have
this problem)?

Not NT specifically, but NTFS. FATx saves the time according to "clock".

If you really think about it, it makes more sense to stamp a file according to
a "constant" GMT. There is only one point in time that your file was saved,
regardless of your point in space. (or the shifted clock).

 

[Bill in Co.]

in message news:[email protected]...


Not NT specifically, but NTFS. FATx saves the time according to "clock".

If you really think about it, it makes more sense to stamp a file according to
a "constant" GMT. There is only one point in time that your file was saved,
regardless of your point in space. (or the shifted clock).

Well, I must still be missing something, as it makes NO sense to me that a
file saved on one system, and then brought over to another system, has it's
date-time stamp "changed"!!

And yes, I *do* recall that happening between work (which used NTFS), and
here at home (where I'm using Win98SE on FAT32), and - it was annoying as
hell to me, since I often pay particular attention to files and their
date-time stamps, for all the changes and mods I make.

Just to give you an idea, "it's a rare day in May" when I'm not either
running SFC, or regedit, or a scanreg/restore operation, or what-have-you,
with some of my "experiments" using various software programs and editions,
and modifications (and some to the registry), and with various C:\Program
File\ directory backups, etc).

So I guess in summary, unless I'm missing something, if I make a file on
June 22 at 10:30 pm, I want that date-time stamp to be PERMANENT for that
file. And not appear to change .. with the wind.

 

[Bob I]

according to



Well, I must still be missing something, as it makes NO sense to me that a
file saved on one system, and then brought over to another system, has it's
date-time stamp "changed"!!

And yes, I *do* recall that happening between work (which used NTFS), and
here at home (where I'm using Win98SE on FAT32), and - it was annoying as
hell to me, since I often pay particular attention to files and their
date-time stamps, for all the changes and mods I make.

Just to give you an idea, "it's a rare day in May" when I'm not either
running SFC, or regedit, or a scanreg/restore operation, or what-have-you,
with some of my "experiments" using various software programs and editions,
and modifications (and some to the registry), and with various C:\Program
File\ directory backups, etc).

So I guess in summary, unless I'm missing something, if I make a file on
June 22 at 10:30 pm, I want that date-time stamp to be PERMANENT for that
file. And not appear to change .. with the wind.

The operative word here is "appear", the time stamp IS permanent. What
you see is the correction for timzone and DST. And it's been that way on
NTFS since the begining (Windows NT 3.1 ).

 

[Stan Hilliard]

The operative word here is "appear", the time stamp IS permanent. What
you see is the correction for timzone and DST. And it's been that way on
NTFS since the begining (Windows NT 3.1 ).

The timestamp of one of my files "appears" to have been "permanently'
changed. The following times are displayed in the Windows Explorer
window. The two files are in the same folder on the same Win98SE
computer. If the computer is adjusting the display and not the actual
file timestamps, I would expect that it would make the same adjustment
to each file.

OUTPUT9.BAS 1/28/01 1:25 AM
OUTPUT9 from HB1.BAS 1/28/01, 2:25 AM

The second file is the copy of the first, whose timestamp changed by
the method that I explained in my top post of this thread.

Stan Hilliard

 

[PCR]

Stan Hilliard wrote:
|
|>
|>
|>Bill in Co. wrote:
|>
|>> Bill Blanton wrote:
|>>
|>>>"Bill in Co." wrote in message
|>>
|>> |>>
|>>>>Rock wrote:
|>>>>
|>>>>>"Bill in Co." wrote
|>>>>>
|>>>>>>Stan Hilliard wrote:
|>>>
|>>>>>>>>>Current situation 4/27/2007 -- during daylight saving time:
|>>>>>>>>>Explorer shows the copies on the XP to be ahead by one hour.
|>>>>>>>>>The clocks of both machines say the same time. The Win XP PC
|>>>>>>>>>clock properties say explicitly that it is on central
|>>>>>>>>>daylight time. The Win98SE PC clock properties say
|>>>>>>>>>(GMT-06:00) Central Time, with a
|>>
|>> check
|>>
|>>>>>>>>>before "automatically adjust for daylight saving changes."
|>>>>>>>>>
|>>>
|>>>>>>>>On an NTFS volume file time stamps are changed with a daylight
|>>
|>> savings
|>>
|>>>>>>>>time change to show the new time.
|>>>
|>>>>>>But why should they be? What kind of "design logic" is
|>>>>>>that?
|>>
|>> It
|>>
|>>>>>>sounds crazy! (although I believe you, I don't understand WHY
|>>>>>>that
|>>
|>> would
|>>
|>>>>>>have been designed into it in the first place; when a file is
|>>>>>>date/time stamped, THAT stamp should be in concrete, and not
|>>>>>>subject to the whims
|>>
|>> of
|>>
|>>>>>>DST or no DST)
|>>>
|>>>>>Time stamp changes with daylight savings
|>>>>>http://support.microsoft.com/kb/129574/en-us
|>>>
|>>>>I wasn't disputing that it did (and I seem to recall this problem
|>>>>too, between work and home), but was asking WHY it was designed
|>>>>this way, on
|>>
|>> the
|>>
|>>>>NT systems (as an offset from GMT). In other words, why was NT
|>>
|>> designed
|>>
|>>>>that way - (so different from the other operating systems, that
|>>>>don't
|>>
|>> have
|>>
|>>>>this problem)?
|>>>
|>>>Not NT specifically, but NTFS. FATx saves the time according to
|>>>"clock".
|>>>
|>>>If you really think about it, it makes more sense to stamp a file
|>>
|>> according to
|>>
|>>>a "constant" GMT. There is only one point in time that your file was
|>>
|>> saved,
|>>
|>>>regardless of your point in space. (or the shifted clock).
|>>
|>>
|>> Well, I must still be missing something, as it makes NO sense to me
|>> that a file saved on one system, and then brought over to another
|>> system, has it's date-time stamp "changed"!!
|>>
|>> And yes, I *do* recall that happening between work (which used
|>> NTFS), and here at home (where I'm using Win98SE on FAT32), and -
|>> it was annoying as hell to me, since I often pay particular
|>> attention to files and their date-time stamps, for all the changes
|>> and mods I make.
|>>
|>> Just to give you an idea, "it's a rare day in May" when I'm not
|>> either running SFC, or regedit, or a scanreg/restore operation, or
|>> what-have-you, with some of my "experiments" using various software
|>> programs and editions, and modifications (and some to the
|>> registry), and with various C:\Program File\ directory backups,
|>> etc).
|>>
|>> So I guess in summary, unless I'm missing something, if I make a
|>> file on June 22 at 10:30 pm, I want that date-time stamp to be
|>> PERMANENT for that file. And not appear to change .. with the
|>> wind.
|>>
|>>
|>
|>The operative word here is "appear", the time stamp IS permanent. What
|>you see is the correction for timzone and DST. And it's been that way
|>on NTFS since the begining (Windows NT 3.1 ).
|
| The timestamp of one of my files "appears" to have been "permanently'
| changed. The following times are displayed in the Windows Explorer
| window. The two files are in the same folder on the same Win98SE
| computer. If the computer is adjusting the display and not the actual
| file timestamps, I would expect that it would make the same adjustment
| to each file.
|
| OUTPUT9.BAS 1/28/01 1:25 AM
| OUTPUT9 from HB1.BAS 1/28/01, 2:25 AM
|
| The second file is the copy of the first, whose timestamp changed by
| the method that I explained in my top post of this thread.

It's what Rock said. NTFS poisoned the date by converting it to an
offset from GMT. That made it variable in appearance, depending upon the
local time zone & whether or not Daylight Savings Time is in effect.
When copied back onto FAT32, it was converted back to a fixed date/time,
& it changed because...

(a) I guess an hour was added to it due to it was on NTFS when the time
change occurred, or
(b) An hour was added to it because the NTFS computer is set to a
different local time zone.

Either way the file date is filled with poison now!

| Stan Hilliard

--
Thanks or Good Luck,
There may be humor in this post, and,
Naturally, you will not sue,
Should things get worse after this,
PCR
(e-mail address removed)

 

[Bill in Co.]

The operative word here is "appear", the time stamp IS permanent. What
you see is the correction for timzone and DST. And it's been that way on
NTFS since the begining (Windows NT 3.1 ).

But it just makes no sense to me to have it be this way. Does it make ANY
sense to you??? It can become a bit problematic just for the reasons
we've been discussing, and it's illogical. If it was a limitation of the
times, I can understand why it happens this way, but since it wasn't
designed that way for the Win9x systems and FAT (which are about as old as
WinNT and NTFS, as I recall), I don't get it.

 

[Bob I]

The timestamp of one of my files "appears" to have been "permanently'
changed. The following times are displayed in the Windows Explorer
window. The two files are in the same folder on the same Win98SE
computer. If the computer is adjusting the display and not the actual
file timestamps, I would expect that it would make the same adjustment
to each file.

OUTPUT9.BAS 1/28/01 1:25 AM
OUTPUT9 from HB1.BAS 1/28/01, 2:25 AM

The second file is the copy of the first, whose timestamp changed by
the method that I explained in my top post of this thread.

Stan Hilliard

Is the file on NTFS anylonger? If not then the issue is the transfer to
the non NTFS system.

 

[... et al.]

in message


Not NT specifically, but NTFS. FATx saves the time according to "clock".

If you really think about it, it makes more sense to stamp a file according to
a "constant" GMT. There is only one point in time that your file was saved,
regardless of your point in space. (or the shifted clock).

I've seen these one hour differences for many years, looking at identical
files on different systems. It applies not only to modified date/time but
also for the date/time shown on the digital-signed property pages.

So nice to see others also noticing and finally get an explanation for it,
even getting a link to a msKB article about it.

It is happening here between machines in my LAN, using WinXP and Win98SE,
*the_thing* however is that there isn't a NTFS partition in sight! Hmmm....

 

[BillW50]

I've seen these one hour differences for many years, looking at
identical files on different systems. It applies not only to modified
date/time but also for the date/time shown on the digital-signed
property pages.
So nice to see others also noticing and finally get an explanation
for it, even getting a link to a msKB article about it.

It is happening here between machines in my LAN, using WinXP and
Win98SE, *the_thing* however is that there isn't a NTFS partition in
sight! Hmmm....

That should be since Windows 98 doesn't use GMT unlike Windows XP. And
the NTFS part only comes in as FAT32 only stores even seconds (not odd).
Or is it just even minutes? Yes I think it is just the latter. So
between the two systems, it could be off an hour plus/minus a minute.

 

[Bill Blanton]

Though it would be the same principle, that may have to do with the network.
The server (or client) may be adjusting for the client's GMT offset when transfering
the file. Do you only see it when DST is in effect?

That should be since Windows 98 doesn't use GMT unlike Windows XP. And the NTFS part only comes in as FAT32 only stores even
seconds (not odd). Or is it just even minutes?

You were right the first time..It's even seconds. NTFS calibrates to the
100-nanosecond. (enh..I looked it up
http://msdn2.microsoft.com/en-us/library/ms724290.aspx

 

[... et al.]

Though it would be the same principle, that may have to do with the network.
The server (or client) may be adjusting for the client's GMT offset when transfering
the file. Do you only see it when DST is in effect?

I know that it is happening.
I know why it is not happening. (I.E. There is no 'NTFS' filesystem present
in my case.)
I don't know why it is happening! I'm not blaming anything, FAT32 vs. NTFS,
Windows vs. WinNT or that network-transfers between such systems are
involved. Not even that it is not my own fault with some screwy setup somehow.

But the exact one hour difference makes one suspect 'Daylight Saving Time'
(DST) is involved somehow right, but ...

.... today looking for some specific examples i find this:

One machine running WinXP the other Win98SE, both using only FAT32
filesystems, both setup the same with regards to Date/Time/TimeZone and both
running with 'Auto-adjust clock for DST' disabled. But this has been
happening also earlier when i've used to leave auto-adjut enabled.

Looking at timestamps on files on CD's they show a one hour difference
between the machines!, and of course this is retained when copying the files
to the HardDiskDrives.

The Win98SE machine: The WinXP machine:
------------------- -----------------
An [IE6Setup.exe] files Modified Timestamp:
2004-02-05 12:00:00 2004-02-05 13:00:00
The digital Timestamp of the same file (NOTE the reverse difference!):
2002-08-29 20:42:42 2002-08-29 19:42:42
Any file on my WinXP CD:
2001-08-18 12:00:00 2001-08-18 13:00:00
Any file on my Win98SE CD:
1999-04-23 22:22:00 1999-04-23 23:22:00

But i have saved a copy of the Win98SE installfolder to the HDD of the WinXP
machine a while back and the files in there is showing the correct timestamp
of '1999-04-23 22:22:00'.

(I might misremember, but i think i've seen these one hour off timestamps
also on the Win98SE side, when WinXP wasn't in the picture.)

In conclusion, no networking involved, no FAT32 or NTFS filesystems
involved. But something in the way i have setup a machine, currently the
WinXP machine, it can translates the timestamps incorrectly for display.