The Halloween celebration is fun for everyone when you dress up in costumes and decorate your home with spiders. But why and how did October 31st become the spookiest day of the year?

Halloween’s origins are connected to Samhain, a Celtic New Year’s Day celebrated on November 1 that is thought to have been around for more than 2,000 years. It was believed that demons, fairies, and spirits of the dead walked the Earth the previous night, when the border between the worlds of the living and the dead was faint. More than a thousand years ago, the Catholic Church changed Samhain’s name to All Saints’ Day, also known as All Hallows‘ Day. The previous evening, October 31, was called All Hallows’ Eve, which was shortened to Halloween. People would leave food out for any spirits that might be lurking around that night. But how did those Celtic traditions evolve to let kids go trick-or-treating in costumes for fun and treats rather than as a form of ghost protection? According to one author, trick-or-treating may be a relatively new tradition that, oddly, may have been influenced by a Christmas custom known as belsnickling. In the eastern United States and Canada, groups of costumed entertainers would visit households to perform little tricks in exchange for food and drink.

Halloween is a great time to frighten one another. Even a little bit, as the days become shorter and the nights get longer.