Halloween (AKA All Souls' Day, Samhain, Allentide, and other names) is not recognized by Filofax, as evidenced by this picture taken from the 2007 Personal diary (it's not in 2006 either). I'm trying to deduce why. Most holidays listed in the Filofax diaries and Information pages are either religious holidays or public holidays (that is, days off from school and work) in one or more large countries. (The following day, Nov. 1, All Saints Day, does appear in the Filofax diary. It's an official holiday in the Catholic and other Christian churches.)
At first, I thought it was because Filofax's British creators considered Halloween an American, commercial holiday, unworthy of recognition. But a little research proved that to be false. Ireland and Mexico get a public holiday for Halloween, although it doesn't always fall on October 31. All Souls' Day is a religious holiday in many traditions, although since it's an "eve" holiday, people can go to school or work that day. An increasing number of countries are joining the Halloween tradition, yet Filofax doesn't mention it even in passing.
I've always been fascinated by the wiccan and pagan Halloween traditions. In my favorite legend, it was the wicca who originated the tradition of dressing in costume for the holiday. But it didn't start out as a way to create a fearful or humorous image. Halloween was the wiccan New Year's Eve, and celebrants would dress as the person they wanted to become in the coming year.
I think that's a great idea.