National Memo Day – 21st May
Did everyone get the memo? National Memo Day is observed each year on May 21.
Memo, short for a memorandum, is a document or other communication, intended to inform a group of people about a particular topic. Memos are used for many different purposes, most often in the workplace. A memorandum is a note or record made for future use and a written message, especially in business or diplomacy.
(source - http://bit.ly/2LYnMxP)