The witching hour is a the time of day when supernatural creatures such as witches, demons and ghosts are thought to appear and be at their most powerful, and black magic at its most effective. This hour is typically past midnight or the "time in the middle of the night when magic things are said to happen."
One of the earliest, if not the first, appearances this term makes is in Washington Irving's short story The Legend of Sleepy Hollow. Here, Irving uses "witching hour" and "witching time" interchangeably.[1] Both terms reference midnight, and are used to conjure in readers a sense of supernatural anxiety. There is little evidence the term has had any practical use prior to this, and that Irving coined the phrase after having grown up around New England and touring areas where the Salem Witch Trials took place.
In several of Shakespeare's plays - specifically Macbeth and Julius Caesar - ghosts and other supernatural phenomena take place around midnight, but the term "witching hour" never appears. But in the play 'Hamlet' we hear young Hamlet saying 'Tis now the very witching time of night'
According to the American horror film The Exorcism of Emily Rose, the term can also refer to the period from midnight and 3am, when a character notes at "3am [is] the devil's hour, as opposed to 3pm, when Jesus was said to have been crucified".[2]
In the context of investing, the term "witching hour" refers to the "last hour of stock trading between 3pm (when the bond market closes) and 4pm EST".[3]