National Derek Day spread through online holiday listings and social media, and British regional newsrooms now mark it on their own accounts. No founder, proclamation or first-observance document has been located for it, and the United States Federal Register holds nothing under the name.
The hangman in the oilfield
The Low Countries sent over more than the name. Around 1600 the word derrick appears in English meaning a hangman, and also a gallows, taken from the surname of an executioner at London's Tyburn gallows who, the Online Etymology Dictionary notes, is often referred to in contemporary plays.
That surname was itself a late borrowing of the same Germanic Theodric, so the hangman and the name share a root. The word then went to work. By 1727 a derrick was a hoisting apparatus for heavy weights, and by 1861 American English had handed it to the oilfields.


