The story
From witching (“of or pertaining to witchcraft or sorcery, or to witches or sorcerers”, adjective) + hour. Sense 1 (“midnight”) was popularized by the reference to the “witching time of night” in the play Hamlet (written c. 1599–1602; published 1603) by William Shakespeare (1564–1616): see the quotation.
First known use, by meaning
- from late 20th c. The hour between 3:00 and 3:59 a.m., associated with demons.
Etymology from Wiktionary, CC BY-SA 4.0.