Length of copyright 
Copyright subsists for a variety of lengths in different jurisdictions. The length of the term can depend on several factors, including the type of work (e.g. musical composition or novel), whether the work has been published or not, and whether the work was created by an individual or a corporation. 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. In most countries (for example, the United States and the United Kingdom) copyright expires at the end of the calendar year in question.
The length and requirements for copyright duration are subject to change by legislation, and since the early 20th century there have been a number of adjustments made in various countries, which can make determining the copyright duration in a given country difficult. For example, the United States used to require copyrights to be renewed after 28 years to stay in force, and formerly required a copyright notice upon first publication to gain coverage. In Italy and France, there were post-wartime extensions that could increase the term by approximately 6 years in Italy and up to about 14 in France. Many countries have extended the length of their copyright terms (sometimes retroactively). International treaties establish minimum terms for copyrights, but these only apply to the signatory countries, and individual countries may grant longer terms than those set out in a treaty.
See also 
- History of copyright law
- List of countries' copyright length
- Perpetual copyright
- Rule of the shorter term
- 17 U.S.C. § 305
- The Duration of Copyright and Rights in Performances Regulations 1995, part II, Amendments of the UK Copyright, Designs and Patents Act 1988
- Nimmer, David (2003). Copyright: Sacred Text, Technology, and the DMCA. Kluwer Law International. p. 63. ISBN 978-90-411-8876-2. OCLC 50606064.