October 31 is Halloween. According to Sister Maureen Shaughnessy, Assistant Secretary for Catechesis and Leadership Formation for the U.S. Bishops' Department of Education, "Halloween gives us the opportunity to help people of all ages reconnect with the Christian understanding of this very popular holiday. Originally this day was celebrated by the Celts in England and Ireland as the end of their year. On that day they remembered all those who had died during the past year."
A number of customs that evolved related to this had to do with ghosts and scary things. As Christians we celebrate this day as the eve of All Saints, and in fact, many parishes and Catholic schools use this opportunity to have young people connect to the lives of saints - their own name saints or patronal saints connected to their parishes or ethnic backgrounds. It provides a time for storytelling, dressing up and celebrating.
More Halloween stuff over at Catholic Mom.