MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

FileDate, or rather Microsoft

  • To: mathgroup at
  • Subject: [mg65080] FileDate, or rather Microsoft
  • From: "Simons, F.H." <F.H.Simons at>
  • Date: Tue, 14 Mar 2006 05:59:57 -0500 (EST)
  • Sender: owner-wri-mathgroup at

I apologize that this question is more a question about strange
behaviour of Microsoft (XP and 2000, but probably all versions) than a
question about Mathematica.

I keep a lot of files on two desktop computers and two laptops, not
connected by a network. So I use a memorystick on which I keep a copy of
the files I am interested in and I wrote very useful program in
Mathematica that updates any of the computers and the memorystick.

That program works very fine almost always. There are only two
exceptions: when the time changes form winter time to summer time and
conversely. When the time change has happened, Mathematica copies ALL
files (more than 200 MB) from the computer to the stick or conversely,
which is very time consuming.

I use the function FileDate for finding the date of the last
modification of a file. It seems that this function takes the date as it
is produced by Microsoft. Now you can do a small experiment. Open the
Windows Explorer with a folder on C: and look at the time of
modification of the files. Then change the setting of the computer from
March to April and refresh the window of the Explorer. All times have
been changed by one hour. Change back the month to March and the times
again change one hour. I cannot think of any reason for this behaviour.
But my problem is that when you do the same experiments with a folder on
the memorystick instead of the hard disk, this does not happen. So when
the time correction takes places, all unchanged files on my hard disk
and the memory stick now differ one hour in time and therefore will be

Does someone have an idea how to switch off this curious behaviour of

Of course I can adapt the Mathematica function FileDate, but I feel it
is better to cure the problem at the source, i.e. the setting of

Fred Simons
Eindhoven University of Technology

  • Prev by Date: Re: Plot resolution
  • Next by Date: Re: Re: Mathematica and Education
  • Previous by thread: Origin Link for Mathematica
  • Next by thread: Re: FileDate, or rather Microsoft