The duration of rights in literary and artistic creation, and the key principle of a limited duration, is one of the less contested or discussed principles of international copyright law. The term of copyright is only minimally addressed by international treaties. The Berne Convention imposes a minimum duration of 50 years after the death of the author but leaves the determination of the term to national States. A more complex picture lurks behind the set of apparently simple rules that could be found at the international level (a limited duration, a minimum of 50 years after the death of the author, and the determination of the duration according to the rule of protection) and hides rather well the failure of international copyright legislation to fix a uniform term of protection throughout the world. As a result, the determination of the end of copyright in a specific work and the consistence of public domain that is constituted by expiration of protection is almost impossible to decide with certainty or stability. This paper aims at exposing this complexity and some its conundrums. It starts by describing how the determination of copyright duration in a work is oscillating between the minimum rules laid down by the Berne Convention and the national copyright laws. A second part explores other reasons for even more fragmentation, by looking at some oddities specific to certain national regimes. A third part addresses the variability of the copyright duration resulting from repeated term extensions and transitory provisions.