The annual fest Samhain Halloween, is traditionally celebrated on 31 October. It is the third and last harvest festival. In the past, animals that could not or should not survive the winter were slaughtered at this time.
With Samhain the Celtic year and also the witches year ends. The dark season begins, during which you look inside yourself, retreat and find peace. All Hallows' Eve, as it is also called, is one of the most important witch festivals of the year.