[rkomar]

Originally Posted by rkomar

I believe that these life+70 rules only apply to books published after 1978, at least in the US. The rules are too convoluted for me, but here are a couple of links that might help you: http://en.wikipedia.org/wiki/Copyrig..._Extension_Act, http://www.gutenberg.org/wiki/Gutenb...pyright_How-To

Okay, I think I'm starting to understand the rules. Prior to 1978, a book was initially copyrighted for 28 years, and it could have an extension of another 28 years if the copyright was re-registered. The rules were changed with the 1978 agreement. Any book that was in the public domain stayed in the public domain (i.e. if it published before 1979-2*28=1923). Any book that was still under copyright in 1978 automatically had copyright extended to 95 years since the date of publication. Any new publications after 1978 automatically got the life+50 year copyright duration (later increased to life+70). So, since 1923, the only books that entered public domain were those published before 1951 that were not re-registered for the second 28 year extension.

So, assuming the rules don't change again beforehand, books published in 1923 that were still under copyright in 1978 will enter public domain in 2018, and books published in 1979 will enter public domain no sooner than 2049.