Halloween occurs this year on Oct. 31. This holidays has changed throughout history. The Celts, who lived over 2000 years ago in what is now Ireland, the UK, and parts of Northern France marked November 1  the start of their new year, so that the night before, Oct. 31, was a time when the living and dead come together. The Christian Church followed up by naming Nov. 1 All Saints Day. The night before became All Hallows Eve, later changed to Halloween.

Like the Celts, other Europeans of the times also believed that the spirits of the dead would visit Earth on Halloween. In order to fool the evil spirits, people would wear costumes such as ghosts and other evil creatures, and therefore people would escape harm.