World Password Day, celebrated annually on the first Thursday in May, was started by information technology professionals to encourage computer users to keep their passwords updated and secure.

Mark Burnett, a computer security researcher, suggested in his 2005 book Perfect Passwords that people should choose an annual “password day” to update their passwords for email and other important services.

Intel Security, inspired by Burnett’s book, declared the first Thursday of May 2013 to be World Password Day, an unofficial holiday aimed at encouraging good password practices such as using unique passwords for every account.