Puzzling timestamp problem between Win7 and Win8.1

[Tegger]

The timestamp in question is Date Modified.

There are two machines in question:
1) a desktop with Win7
2) a laptop with Win8.1

Both machines are using the same time zone and are using the same NTP server. Their clocks (both CMOS and Windows) show the exact same time.

Situation 1:
-- I use the Win7 box to copy some files to the Win8.1 box.
-- I use the Win7 box to view the newly-copied files on the Win8.1 box.
-- Timestamps match.
-- Now I go to the Win8.1 box and look at the newly-copied files from there.
-- Timestamps are off by ONE HOUR.
In other words, the Win8.1 box is showing me a DIFFERENT Date Modified than what the Win7 box shows me, for the SAME files at the SAME time in the SAME location!

Situation 2 (sit 1 in reverse):
-- I use the Win8.1 box to copy some files to the Win7 box.
-- I use the Win8.1 box to view the newly-copied files on the Win7 box.
-- Timestamps match.
-- Now I go to the Win7 box and look at the newly-copied files from there.
-- Timestamps are off by ONE HOUR.
In other words, the Win7 box is showing me a DIFFERENT Date Modified than what the Win8.1 box shows me, for the SAME files at the SAME time in the SAME location!

Specifically,
If I go Win7 --> Win8.1, the timestamp falls BACK by one hour.
If I go Win8.1 --> Win7, the timestamp JUMPS AHEAD by one hour.
Remember that both machines have the same clock time!

I've Googled, but nobody else seems to have this specific problem.

Any ideas?

 

[cpayne5]

Create a brand new file on one of the computers and transfer it to the other one. Do the times still jump?

 

[Tegger]

Originally Posted By: cpayne5
Create a brand new file on one of the computers and transfer it to the other one. Do the times still jump?

Yes.

This problem does NOT happen when I use the Win7 desktop and any other Win7 box to copy files back and forth.

This ONLY happens when the Win8.1 box is one of the participants in the file transfer.

 

[shanneba]

Does one of the computers have a different setting for "adjust for daylight savings time automatically"
That could cause a 1 hour difference.

Also make sure both are displaying the same date, either modified or created date.

 

[NMBurb02]

So if you modify the file, immediately copy from Win8.1 to Win7 and then immediately check the file on Win7 it will show that the file was modified one hour in the future?

 

[Kawiguy454]

Have you tried a copy program like robocopy, beyond compare or synctoy?

Starting with win7 there are a few filesystem caching schemes that may be causing problems. In our corp network share environment winXP does very fast network searches. Win7 and newer there are slowness issues and problem is embedded in the windows explorer code.

Win8 and win10 are probably newer and more improved versions of that gimmickery.

 

[Tegger]

Originally Posted By: NMBurb02
So if you modify the file, immediately copy from Win8.1 to Win7 and then immediately check the file on Win7 it will show that the file was modified one hour in the future?

That is exactly what happens.

The clocks, time zones, NTP settings, and any and all other time settings are identical between the two machines.

The problem manifests whether or not I do a manual transfer or use a file-synchronization program. I have Vice Versa Pro, which has worked famously for me every single working-day since 2006, through Win XP and Win7.

In fact, it was Vice Versa that first made me aware of the problem, since it shows the ahead/behind timestamp that I will actually end up with, not the timestamp shown in Windows Explorer.

 

[Tegger]

I finally found the problem.

My region uses Daylight Savings Time. Win7 and XP automatically set their clocks to "automatically adjust time for DST". The Win8.1 installation DID NOT DO THIS. It left that box UNCHECKED.

That means that there was confusion between the Win7 box and the Win8.1 box, since one was expecting a DST time and the other wasn't.

Why was Win7 smart enough to know that if I'm in the Eastern time zone for North America then DST is required, but Win8.1 isn't smart enough to do that? Needless confusion and wasted time!