Who came up with the date when Christmas decorations should be taken down?
This ties in with the one about the 12 days of Christmas. No-one decided it as such – it would be normal for the decorations to be left up for the period of the celebrations. At the end, they would be getting rather tatty, as they were originally natural greenery – holly and ivy and other evergreen boughs especially before Christmas trees came in from Germany. The thing about leaving them up till Easter (or all year in some places) if you fail to remove them is one of those superstitions that arise quite naturally. The greenery should be burned when finished with, which has a nicely pagan sound to it, probably because it took the problems of the old year with it. Nowadays, having your Christmas tree shredded probably counts as the same – unless it’s an artificial one!