I just found this info on Wikkapedia,
" In European folklore, the witching hour is the time when supernatural creatures such as witches, demons and ghosts are thought to be at their most powerful, and black magic at its most effective. This hour is typically midnight, and the term may now be used to refer to midnight, or any late hour, even without having the associated superstitious beliefs. The term "witching hour" can also refer to the period from midnight to 3am, while "devils hour" refers to the time around 3am."
I did a little other reading on net the Witching hour apperas to vary from tradition to tradition, also the term was first used in Mary Shelly's Frankenstien.
Posted hear because I did not want to hijack Tammi's post.
Later,
G