Why do file timestamps compare differently every time change?

Your response to the subject was great, no one I've asked before had any idea. Yours is a site I will visit often.
Thank you very much!

Nice post- simple explanation for a maddening problem. Add the complexity of EXIF photos and working in Australia / US where the time is about 12 hours opposite. I can't tell you how many photosets I have where I've taken photos from 10am to say 4pm and they get split into Tues 10pm through Wed 4am.

Another fun project:

Save a file to a FAT device on your computer. Change your timezone (or go to another computer in a different timezone) and the date/times will no longer match.

Le sigh.

Leo, out of curiousity, do you know of a Universal File Format other than FAT that supports UTC and works between Linux, Windows, and Mac?

Actually NTFS is close to being universal these days. There's both Linux and Mac support, though often as an add on you need to install.

20-Nov-2009

One other, rather obvious solution: If you can tolerate your pc's time being 1 hour off for six months every year, would be to go into your control panel (Time Zone tab in Date and Time Properties) and un-check the 'Apply Daylight Saving's Time' box.

While this sounds good in theory, the problem is that your clock being off with the rest of the world can result in odd behaviours, right down to not being able to login to various web services or more.

26-Nov-2009

I wondered about the GMT/NTFS part. I generated a notepad file, checked the timestamp..it's PST. The machine is XPP, HD is NTFS.

I'd not heard the GMT timestamping of files written under an NTFS. The file I just saved doesn't show that to be so.

I'm assuming 'timestamp' to be the time shown in a Windows Explorer window..or in the properties window of a particular file

What am I missing?

Thanks!

GMT is how it's stored. When it's displayed - as in Windows Explorer - it's converted to your local timezone. So you never see GMT times (unless that's your timezone, of course).

26-Nov-2009

I DID read it.

...just not very good! I KNEW I was missing something.

The third time through I see what I'd missed.

The Helen Reddy Sped Reddin course strikes again!

Thanks, Leo.

Some synchronising tools (e.g. GoodSync) will ignore apparent time stamp differences of exactly one hour. Useful if you need to sync between FAT32 and NTFS drives.

I found a small utility called Righttime (try googling it), which is free and relatively simple to use. It will change the timestamp of the files you indicate to either make them one hour 'older' or 'younger' -- the trick is knowing what to use when.

The frustrating problem with the seasonal time change is that EXISTING files get one hour taken off every time we switch to Standard Time from Daylight Savings Time!

In other words, ALL files created (I meant, 'modified', in Microsoft Newspeak) during Daylight Savings Time get one hour subtracted (in Windows Explorer and any application using the File System) when we revert to Standard Time!

How stupid is that!!! Why can't Windows Explorer show me the real time for files modified during Daylight Savings Time? Any idea how this obnoxious behaviour can be corrected?! I can't seem to find a solution online anywhere!

Your suggestion is USELESS when copying files between non-windows platforms and a windows machine. IE: My Blackberry to a network share on a NAS via a Windows PC. So you want me to NTFS format my Blackberry??? yeah.

File timestamping needs to be standardized across platforms. Daylight savings time is idiotic in our modern age anyway.

To post a comment on "Why do file timestamps compare differently every time change?", please return to that article's main page.