Reformation Day: 4 facts to know about the other Oct. 31 holiday

For many Americans, the last day of October is a time of trick-or-treating, costumes, candy and various spooky things from horror movies to haunted houses.

Halloween, the holiday most known for its playful scaring and bags of sweets, is most closely associated by mainstream culture with Oct. 31.

However, for hundreds of churches across the United States and many others throughout global Protestantism, Oct. 31 is a time to remember the birth of the Reformation.

Known as Reformation Day, many churches hold special services either on the day itself or the preceding Sunday. 

Below, in no particular order, are four facts about the observance and history of the Reformation.