The only holiday my family decorates for is New Year/Christmas. I usually start decorating my room first, either on last weekend or 5-3 days before New Year. We put up tree and the rest of decorations on 29th to 31st, depending on how busy we are that year and if one of those days falls on weekend. I suspect this year all decorations will go up on 31st and there is no guarantee that I won't run tree-hunting on evening of 30th or on 31st again.
Tree and decorations stay up for as long as father and I can get away with leaving them up. Meaning all decorations except tree and ones in my room are down soon after Christmas. The rest we take down around next weekend after 13th - New Year's day Old Style.