October 31. Also called Samhain by the Wiccan and Pagan communities. This holiday is widely celebrated by people of all faiths with costume parties and trick-or-treating. But this night also marks the Wiccan new year. In the wheel of the year, Samhain is the night when the God dies and leaves the Goddess alone until Yule, when he is born again. Halloween/Samhain is a time when the doors between the worlds are said to open, stirring up much ghostly and otherworldly activity.