I'm working with a formerly closed-source project whose official first release under that product name was in 1997. Development on it slowed and was abandoned, then released as Apache 2.0 in 2012. The copyright dates in the file headers of that open source publication said:

Copyright 2012 PROJECT Corp.

PROJECT is a trademark of PROJECT Corp.

Licensed under the Apache License Version 2.0 (the "License"):
you may not use this file except in compliance with the license...
blah blah blah

PROJECT Corp has not really been involved in the development since the open source release, but others have. Requests to PROJECT Corp for involvement and/or support have been largely unheeded. I was considering changing this to:

Copyright 1997-2012 PROJECT Corp.
Copyright 2012-2015 Project Open Source Contributors (see CREDITS.md)

PROJECT is a trademark of PROJECT Corp.

Licensed under the Apache License Version 2.0 (the "License"):
you may not use this file except in compliance with the license...
blah blah blah

My question is about not refreshing their copyright date to read Copyright 1997-2015. I feel it's more accurate to convey the date ranges of involvement with the source by not updating it. But additionally, I wonder if I would even be authorized to do it on their behalf.

I'm not trying to make PROJECT Corp mad--they may not even want to be associated with the derived code anyway! But the codebase does have active developers who want to keep the file headers current.

  • 2
    Copyright has to do with dates of publication, not dates of "involvement". If they first published the source openly in 2012, then their copyright date of 2012 is proper. Commented Dec 7, 2015 at 23:27
  • @GlennRanders-Pehrson I'd agree, but if one is continually updating an open source codebase e.g. on GitHub, then "participation"="publication". And with a source file, even changing the copyright date alone counts as a "new publication" (otherwise one gets into the slippery slope of "how much change to a file makes it a new file...) Commented Dec 7, 2015 at 23:44
  • When did it actually become open source? If earlier than 2008 it had to be somewhere other than GitHub. The first copyright date should correspond to whatever that date was. Commented Dec 8, 2015 at 1:39
  • @GlennRanders-Pehrson Can't the copyright date on a work of code span from previous to its publication, for instance if the binaries were published? Can you only label a source file's copyright date from when you've given it out? Commented Dec 8, 2015 at 1:50

1 Answer 1


Paragraph 4.3 of the Apache 2.0 license requires you to retain the copyright notice. In my opinion (I am not a lawyer) that would not allow you to change the copyright date from 2012 to 1997-2012, even if the latter is actually more accurate.

The last part of paragraph 4 allows you to add your own copyright line.

If you feel the need to credit the original copyright owner with work prior to 2012, I suppose you can do it in some other manner, such as in a "credits", "acknowledgments", or "project history" document.

The Free Software Foundation has some advice on the matter of displaying copyright years. While they were talking about GPL licenses, their advice seems to be generally applicable:

The copyright notice should include the year in which you finished preparing the release (so if you finished it in 1998 but didn't post it until 1999, use 1998). You should add the proper year for each release; for example, “Copyright 1998, 1999 Terry Jones” if some versions were finished in 1998 and some were finished in 1999. If several people helped write the code, use all their names.

For software with several releases over multiple years, it's okay to use a range (“2008-2010”) instead of listing individual years (“2008, 2009, 2010”) if and only if every year in the range, inclusive, really is a “copyrightable” year that would be listed individually; and you make an explicit statement in your documentation about this usage.

I'm not sure whether that is grounded in copyright law or in FSF opinion.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.