April 30 has long been celebrated in Mexico as El día de los niños (Children’s Day.) Since 1997 it has been celebrated in the US and other places as El día de los niños/El día de los libros (Children’s Day/Book Day) shortened to simply Día.
It is a day to bring together children, books, languages, and cultures. It is both a daily commitment and an annual celebration to focus on the joys and wonders of childhood and the importance of literacy.