IIRC the witching
hour is
midnight/
12:00am/
2400 hours. Anyway it is some time at night and refers to the time of night when all the
witches,
ghouls,
ghosts, and
monsters come out.
In stock market terms it refers to the closing of the market (see double witching hour and triple witching hour).
Also a movie or two, a band, many books, websites, comics, and more. Seems to be a very popular name.