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

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

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.."

"Stan Hilliard" wrote in
message
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.."

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/200...dst-patch.html

--
Bill

"Stan Hilliard" wrote
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]

On Sat, 21 Apr 2007 13:03:47 -0700, "Rock" wrote:

"Stan Hilliard" wrote
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

Stan Hilliard wrote:
On Sat, 21 Apr 2007 13:03:47 -0700, "Rock" wrote:

"Stan Hilliard" wrote
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.

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)

"Bill in Co." wrote

Stan Hilliard wrote:
On Sat, 21 Apr 2007 13:03:47 -0700, "Rock" wrote:

"Stan Hilliard" wrote
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.

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

--
Rock [MS-MVP User/Shell]

Rock wrote:
"Bill in Co." wrote

Stan Hilliard wrote:
On Sat, 21 Apr 2007 13:03:47 -0700, "Rock" wrote:

"Stan Hilliard" wrote
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.

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)?

"Bill in Co." wrote

Rock wrote:
"Bill in Co." wrote

Stan Hilliard wrote:
On Sat, 21 Apr 2007 13:03:47 -0700, "Rock" wrote:

"Stan Hilliard" wrote
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.

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)?

Ask the designer(s).

--
Rock [MS-MVP User/Shell]

"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).