Challenge: how do you prove a file date?

[Breakaway]

For example, let's say you have a file that you made (words or images or video) and you want to use this file as proof incase in the future someone in court challenges you about the creation date. The problem that arises is that with certain dates, I understand that a programmer can tamper with it, thus making it un-reliable.

[Minsc]

You can change the creation/last modify/last access dates to whatever you want. You could also change the contents of the file so there's nothing in the file that could accurately determine when it was made.

If you uploaded the file somewhere, the place you uploaded it to would know the date you uploaded it(probably).

[Brutha]

U.S. Copyright Office - Literary Works Registration

I don't know whether uploading a file somewhere will help you in court.

[Caveman Joe]

Hmm. That sort of thing can always be faked.
You could take the old-school method of printing the data or burning it to a CD and then posting it to yourself, but CD's and DVD's don't last forever by any stretch of the imagination.
You could pull the hard drive and put it in a safety deposit box, but will you still have a machine that can read said data in twenty years' time? And, with the average operating lifetime of a hard drive being less than three years these days, would you still be able to retrieve the data even if the drive has sat unused?
Tricky question.

[Baltar]

Originally Posted by Breakaway

For example, let's say you have a file that you made (words or images or video) and you want to use this file as proof incase in the future someone in court challenges you about the creation date. The problem that arises is that with certain dates, I understand that a programmer can tamper with it, thus making it un-reliable.

It doesn't take a programmer to modify the timestamp of a file. In Unix, touch can be used to do it. In Windows there are programs you can easily find that will do this.

Originally Posted by Caveman Joe

You could take the old-school method of printing the data or burning it to a CD and then posting it to yourself

No, no, no, and no. This is a copyright myth. Please read the US copyright office FAQ:

I’ve heard about a “poor man’s copyright.” What is it?

The practice of sending a copy of your own work to yourself is sometimes called a “poor man’s copyright.” There is no provision in the copyright law regarding any such type of protection, and it is not a substitute for registration.

By law you get copyright protection for any work that's created, registered or not. However, you have to register to go to court. You can register the copyright at any time after the work's creation, even after someone copies you. One notable case in recent years was Novell registering the Unix copyright, and SCO suing them because they asserted that they owned the copyright. It was recently announced that SCO lost, and Novell indeed owns the copyright.

[tobyhede]

For my code I use a third-party subversion host, which means I have a continuous chain of code going back to the first line, managed by an independent third party. Not perfect, but it's something.

If you are genuinely worried, I am sure a lawyer may be able to help. Take the file, cite it's existence, lock it away.

I think tape lasts a long time, but you could always burn a bunch of disks, and use a flash drive ... depends how long you need to keep it for ...