A short history of proofreading

National Proofreading Day (8 March), as you may have guessed, “promotes mistake-free writing” – an aspiration as old as the written word. Medieval manuscripts are full of errors and amendments by scribes and copyists, as well as marginal comments such as “New parchment, bad ink; I say nothing more” and “That’s a hard page and a weary work to read it.”
National Punctuation Day

National Punctuation Day – as the sharp-eyed among you will have realised from the two serial/Oxford commas in the mission statement above – is an American invention.
National Grammar Day

Established in 2008 by Martha Brockenbrough, founder of the Society for the Promotion of Good Grammar (SPOGG), National Grammar Day is celebrated (or possibly ignored) on 4th March.