My parents started collecting Christmas decorations when they got married in 1974. As much Disney as there is there, there is an equal amount of non-Disney, if you can believe it. About 1995, my parents decided to specialize in just Disney decorations.
For forever, we had a rule that Christmas decorations could not be put up until after the Thanksgiving dinner dishes were cleaned. But in 1998, my parents joined a Disney collector's group called the NFFC, and they started hosting the yearly Christmas party. There was no way to get everything up by the time of the party, if we started after Thanksgiving, so the new rule became "November 1st." The party would be around the 10th of December, so that's about 40 days worth of work.
The going down part is a lot faster, less than 2 weeks.
The pictures are from 2002, the last year they went up because the decorator, (ie. me) moved from Washington to Arizona.