@ilyess Why? Copyright dates only need updating when text is (substantially) modified.
@ilyess The reason I was aware of this was maintaining open source software with copyright headers in source files. There are even utilities to help automate this particular task, e.g. https://github.com/fbiville/headache.
@underlap I love the name of that utility :P
@ilyess Yeah, a friend of mine, Florent Biville wrote it. He has a great sense of humour.
@underlap You're right! Copyright doesn't expire every year and doesn't need updating unless substantial modifications have been published. Thanks for pointing that out.
Here's an extract from Wikipedia: "In most of the world, the default length of copyright is the life of the author plus either 50 or 70 years. In the United States, the term for most existing works is a fixed number of years after the date of creation or publication."