Well it's a mas that's been kept in every church on All Hallows Day (or All Saints Day). Its' a catholic holliday on the first of November, meant to honor all the saints. Now I don't really care for all that except, it's an offcial holliday here and if I have to work on that day, I'll be paid double ánd get an extra day of leave.
The day after that it's All Souls Day. A day to remember all the dead. It's not an offcial holliday unfortunately.