No offence, but for me the time to put the decorations up is Christmas Eve, then you get up on Christmas morning, and POW, it's Christmas.
My Wife likes them up earlier, so we compromise, they go up when I've got fed up with her nagging me to get them down from the loft.
The thing with Decorations that gets me, is when, a couple of days after Boxing day, you see people taking them down, they've had them up for so long, they've got fed up with them. What happened to the 12 days of Christmas.