An event every year that begins at 00:00 on day 23 of June, repeating indefinitely
When: June 23
First occurrence: .?.
Celebrating the anniversary of U.S. patent on the Sholes and Glidden typewriter in 1868.
This was not the first typewriter to be invented, but was one of the first to be commercially successful and also the first typewriter to have the QWERTY keyboard layout.