FileDate, or rather Microsoft
- To: mathgroup at smc.vnet.net
- Subject: [mg65080] FileDate, or rather Microsoft
- From: "Simons, F.H." <F.H.Simons at tue.nl>
- Date: Tue, 14 Mar 2006 05:59:57 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
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 updated. Does someone have an idea how to switch off this curious behaviour of Microsoft? 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 Windows. Fred Simons Eindhoven University of Technology