I didn't find out that World Book Day was yesterday until today, but I find it a little strange that it's described as "the biggest annual celebration of books and reading in the UK and Ireland." Shouldn't it be "North-Western Europe Book Day" or maybe even "UK and Ireland Book Day" rather than World Book Day?
Regardless, I find it difficult to keep up with all of the rather pointless "literary" days that have been created. There's National Grammar Day (which was also yesterday, coincidentally; apparently the two groups didn't compare calendars before they set up their websites), National Punctuation Day, National Science Fiction Day, National Poetry Day (UK), World Poetry Day (United Nations), Teen Literature Day, International Children's Literature Day, World Intellectual Property Day, World Book and Copywrite Day, National Day on Writing, National Reading Day, National Read Across America Day, Tolkien Reading Day, the National African-American Read-In, and International Literacy Day. I'm assuming this list is missing about a bajillion other "literary" days, but you get the idea.
To be honest, the only "book day" for which I can really muster any enthusiasm is Free Comic Book Day--and that's mostly because I like anything with the word "free" in the title. I think that celebrating individual writers (like Robert Burns) is a great way to expose kids (and adults, come to think of it) to poets and authors who made a significant cultural impact, but the endless list of "holidays" that are celebrated mostly in the blogosphere reminds me of the endless list of patron saints that are celebrated mostly at Catholic Online. It's mildly interesting but ultimately just a lot of paperwork.