World Intellectual Property Day is observed annually on 26 April.

The event was established by the World Intellectual Property Organization (WIPO) in 2000 to “raise awareness of how patents, copyright, trademarks and designs impact on daily life” and “to celebrate creativity, and the contribution made by creators and innovators to the development of societies across the globe”. 26 April was chosen as the date for World Intellectual Property Day because it coincides with the date on which the Convention Establishing the World Intellectual Property Organization entered into force in 1970. This event has been criticized by a number of activists and scholars as one-sided propaganda in favor of traditional copyright, ignoring alternatives related to copyleft and the free culture movement.

Links:
World Intellectual Property Day

What is copyleft? / Copyleft: Pragmatic Idealism