This year's International Literacy Day.

From Grammarly:

This year we had International Literacy Day on Sept. 8. The theme of International Literacy Day 2015 is Literacy and Sustainable Societies. Literacy is a key driver for sustainable development. Literacy skills are the prerequisite for the learning of a broader set of knowledge, skills, attitudes and values, required for creating sustainable societies. At the same time, progress in areas of sustainable development, such as health and agriculture, serves as an enabling factor in the promotion of literacy and literate environments.  - UNESCO

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